TRANSLATIONS INTO ENGLISH OF LORENZ SPENGLER'S PAPERS ON BIVALVES (1783-1798). PART 4. -1792: THE...

Phuket Marine Biological Center Special Publication 25(2): 557-570 (2001) 557

Translations into English of Lorenz Spengler's papers onbivalves (1783-1798). Part 4. -1792: the genera Pholas and Teredo

Jorgen Hylleberg & Jorgen Knudsen

Hylleberg,J. & ].Knudsen, 2001. Translations into English of Lorenz Spengler'spapers on bivalves (1783-1798). Part 4. - 1792: the genera PhDlas and Teredo. Phuket Marine Biological Center Special Publication 25(2): 557-570.

Spengler (1792) described 11 species of Pholas and 4 species of Teredo. Of these hehimself considered Pholas papyraceus as a new species (from the North Sea). Heredescribed two species which Chemnitz already had described but sinceChemnitz is unavailable (ruling by ICZN), Spengler must be quoted as the authorof the species Pholas quadrizonatus Chemnitz (= Parapholas quadrizonatus (Spengler,1792)), and Pholas explanatus Chemnitz (= Pholas explanatus Spengler, 1792). Hereferred to Adanson as author of Teredo norvegicus. Also in this case Spenglermust be quoted as the author (= Nototeredo norvegicus (Spengler, 1792)).

Jorgen Knudsen. Zoological Museum, University of Copenhagen, Universitetsparken15,2100 Copenhagen 0, Denmark.Jorgen Hylleberg. Institute ofBiological Sciences, Dept. ofMarine Ecology, Finlandsgade14, 82'00 Aarhus N, Denmark.E-mail: [email protected]

INTRODUCTIONSpengler (1792) described 11 species of Pholasand 4 species of Teredo. Of these he onlyconsidered Pholas papyraceus as anew species(from the North Sea). He redescribed andcommented on some of Chemnitz' species andsince Chemnitz is unavailable, Spengler mustbe quoted as the author of the species No.8.Pholas quadrizonatus Chemnitz = Parapholasquadrizonatus (Spengler, 1792), and No.5.Pholas explanatus Chemnitz = Pholas explanatusSpengler, 1792. He referred to Adanson asauthor of Teredo norvegicus. Also in this caseSpengler must be quoted as the author (No.13. Teredo norvegicus Adanson = Nototeredonorvegicus (Spengler, 1792))Other species cited by Spengler have beenmoved from the genus Pholas to other genera:No.2. Pholas costatus Linne = Cyrtopleuracostata (Linne), No.4. Pholas candidus Linne =

Barnea candida (Linne), No.7. Pholas striatus

Linne = Barnea striatus (Linne), No. 10 Pholascrispatus Linne = Zirphaea crispata (Linne).

For general introduction see this volume25(2): 529-538.

4. Spengler 1792. Danish title:Betragtninger og Anmarkninger ved denLinneiske Slagt Pholas blant de man$eskalledeMuskeler, med dens hidindtil bekitfndte gamleog nye Arter, samt den dermed i Forbindelsestaaende Slagt Teredo Linn.

Translation: Considerations and notes on theLinnean genus Pholas among the multivalvedbivalves with its hitherto known old and newspecies, together with the related genus Teredo.

By Lorenz Spengler.(Read on 25th February 1791).

In the paper which I read before the Society

558 Tropical Marine Mollusc Programme (TMMP)

last year I deliberately selected among themultivalved shells the genus which is calledLepas, with the purpose, as far possible, toplace it in a better systematic order by meansof suitable, exactly defined, subdivisions, thanwas hitherto the case, and also to give theNature lover and collector better knowledgeof these animals; I also do not think that I amwrong in believing that I have not taking uponmyself a useless task, when this time Iendeavour, for the lovers of shells, to treat thethird genus of the multivalved shells namelythe pholads, to make it easier for scientists, bymeans of unmistakable characteristics, toseparate them from each other, and give themthe right place according to their differences.

In comparison with the preceding genusLepas, the present one is only small, but it isdifficult to obtain intact specimens with theiraccessory shells (valvis accessoriis and thisdrawback must be a great hindrance to thewriters who wish to consider the species ofthis unknown genus.

Just as Lepas cannot exist alone withouthaving other bodies to which they could attachthemselves, thus the pholads also could notlive, exposed as they are, to the continualmovement of the sea and the waves, becausethat part of the animal which represents thefoot in the bivalves, which they use forcrawling and attaching themselves to hardbodies is not of the same construction in these,so as to be used in the same way; therefore, inan almost incomprehensible way, theyunderstand to find their burrows in thick seamud, in all kinds of clay, in abandoned corals,in wood etc., so as to become completelyhidden from the human eye (except for a verysmall opening above). They remain incompany with each other, and it is noteworthythat the tr4-e pholads, and among these, thosewhich obtain a considerable size, always boretheir dark burrows close to each other invertical direction so that the broad end isdirected downward; an exception is howeverthe wood pholad, which bores into the timberin all directions, and when they meet eachother with their burrows, they usually deviate

to the side. Many authors and among thesethe conchologists, in their writings, in whichthey consider the genus Pholas, haveexpressed their surprise that this animal hadthe strength to bore into often hard stones,without it being possible, on the outside of thestone, to discover the smallest hole by whichit could be revealed that a shell animal washidden inside. They had the most peculiarideas when trying to explain how this wonderof Nature took place. It is true that Myt.Lithoph. is found in limestone harder thanmarble, on the French coast near Toulon, aswell as at the Italian harbour Ancona, wherealso the pholads occur; but this mollusc speciesis not either a true pholad, although it isconstantly confounded with this by theauthors; on the contrary, it belongs to thebivalves, and the only feature, which it has incommon with the pholad, is that it seeks itsburrow in stones; however, an importantexception must be made, since both, asdifferent species of shells, occupy quitedifferent substances into which they hide. Imust therefore state, in this place, anobservation, which was hitherto unnoticed.Mytil. Lithoph. has a much stronger shell thanthe pholads usually have, and their cylindricalshape, which is rounded on all sides, makes itmuch easier for the animal to bore and enlargeits dark house, necessitated by its increasinggrowth. The pholad however has a thin, easilybroken shell, and Jhe small accessory shells,which are extremely thin and attached to theanimal only by a ligament, makes it difficult,if not quite impossible, for this mollusc speciesto use any strength when it would find itnecessary to enlarge its house in a fairly hardbody. According to what I have stated above,the bivalve Mytil. Lithoph. can always chose astronger substance when it wants to hide.When it is young, perhaps also when it is stillenclosed in the egg, it will therefore bury itselfinto the beach in the calcareous soil, which wasformed by dissolved animals and shells, bywhich the surface of the beach is covered; thissoil, later on, due to the slimy and oily seawater, collects into a mass, and therefore is


transformed into hard limestone, when thewater recedes, and there is free admittance ofthe air. The pholad, on the other hand, seeks amuddy and clayey bottom: whether it be veryyoung; or already in growth, but such softcovering will always be harmless to its easilybreakable shell, Thus it will sink vertically intothe soft clayey mass,which surrounds it onall sides. by means of its Siphon, which isprovided with a double canal, this animal, likethe other species of bivalves, which usuallyinhabit foreign bodies, bores only a small hole,which reaches to the water, through whichhole it sucks nourishment and discharges itswaste products. The sorts of clay maypresumably also obtain a considerablehardness, when they are exposed to the freshair, but they will never obtain the samehardness as the above-mentioned calcareoussoil, for which reason the true pholads areseldom or never met with in this soil.

Adanson in his Histoire Naturelle duSenegal writes about the pholads on the coastthere that at the mouth of the Niger they aresitting in rather compact mud. Reaumur, inan excellent paper in Memoires de l'Academiedes Sciences for the year 1712, gives a detailedaccount of the pholads, which are caught ingreat quantities on the French coast nearPoitou d'Annis and Toulon, where they areeaten; at this place they are generally sittingfirmly in a blue type of clay. The same pholads,which likewise are hiding in blue clay, we findin the Adriatic, on the low beach near Ancona,where they are also eaten like oysters. On thecoasts of England and Ireland they are alsoabundant in clay, where, when the waterrecedes, they are discovered on account of thenumerous small holes. In the East Indies onthe Coromandel Coast on the northeasternside of Sitta-Pachanterie (Dr. Konig writes me)the whole beach consists of a blackish-greytype of clay, in which are found several rareshells, but mainly pholads. According toanother account from this naturalist, he foundin the China Sea and the Gulf of Siam, at themouth of the river Qunda, in a muddy bottom,at half a man's depth, the rare Phalas, which I

discussed in detail in a paper, which I readbefore Det Kongelige Danske VidenskabersSelskab, it is found together with the copperplates in the third part of the new collectionspublished by this Society. For this reason I shallnot here repeat the many observations on thisspecies. Therefore, I only wanted to state thedata which were based on experience, in orderto show that the pholads are unable to boreinto hard stone and rock, which phenomenonso many authors of natural history have beenengaged on explaining and endeavoured todiscover the way, in which this Nature wondertook place. Yes, they even ascribed to the Phalasanimal a stone-dissolving liquid by which tofacilitate the work, when it would bore aburrow into the hard rocks. Experience showsthat different species of bivalves, like thepholads, know how to seek their habitats,partly in coral masses and other soft limestones, partly in mussel and snail shells. Butit must be supposed that these species of shells,so different as they may even be, did not forcetheir way from outside into the foreign bodies.Madrepores and porous lime stones alreadyhave so many burrows ready that the youngoffspring of these bivalve species, withoutmuch effort, could chose a house there, whenthey start their work with enlarging andexpanding their burrow in proportion to theirgrowth. But how will it go these intruders,when they would take up their quarters inshells of mussel and snail, since these are builtof a much harder substance than those are? Itis easily understood tha'nhin-valved bivalvesand snails are not fit to hide foreign musselsunder their shells. But the thick-valved shellsobtain their thick shells only with age,especially those which annually, besides theirusual expansion, either add new volutes, e.g.the dog whelk, or develop new layers tostrengthen the old ones, as for instance theStrambi or wing snail and the large pearl oysterMytilus margaritifera and many others. Thisway in which th~ shells grow and becomethicker is a convenient occasion for the youngoffspring of the small mussels which hide inthe shells of others, because they can mix with


the new, added substance; for at that time ithas not still by far become hard, and for thatreason due to its cylindrical build, and bymeans of the considerable incisions on bothvalves, which it can use iRstead of a file, themussel can be strong enough, by its incessantmovement, to enlarge and expand its burrowaccording to necessity. I know no other bivalvespecies, which suffers .more from intrudersthan the old full-grown shells of the abovementioned Mytil. margaritif. A small species ofMyt. Lithophag. frequently sneaks in betweenthe outer and inner plate of the shell so thatthe whole bivalve, owing to the many holes,becomes quite useless to the artists.

I shall now again - as I intended - revert tothe genus Pholas, and must add somethingabout those which usually bore into wood, andto these belong Pholas pusillus Linnaei. Alreadyin the year 1779, when this Pholas was still rare,and by the few authors, who had statedsomething about it, very incompletely andindistinctly described, I have described this indetail in a paper with accompanying drawingin Beschaftigungen der Berliner GesellschaftNaturforschender Freunde 4th volume. Ireceived the originals from Tranquebar, whichare intact and large. A few years later, we hereobtained this, formerly so rare Pholas, in greatquantities, when the bottom of a ship,belonging to the East-Indian Company, whichwas to be sheathed, instead of the otherwiseusual wood borer (Teredo) was completelyperforated by this five-shelled wood pholad,which unusual event was a welcome presentto the shell collectors.

Finally, I must show the lovers of conchologyhow, by definite characteristics, they canseparate the genus Pholas from the otherbivalve genera. This information is so muchless superfJ-uous, since many authors, notablythe old ones, generally confounded the truepholads with the bivalves, which usually boreinto corals, shells and other foreign bodies.

The true and genuine pholad has three, four,five or six shells, which are different in eachspecies of the genus. Like the Bivalves, theyhave two big shells; most of the other smaller

ones are very thin and not connected by anylocking tooth with the two big shells, but onlycover the gaps found between these in theplace where they do not touch or are attachedto the same by a fleshy membrane, which fromthe inside fills this opening. The broadest andlargest of these accessory ,shells are alwayssituated in the place, where both umbones(Nates) of the large shells touch each other, sothat on both sides there is either a thin plate,as in Pholas Dactylus, or a somewhat strongerone, covering both umbones, under this coverhiding two other smaller - but still peculiar shells, which are found in the East-Indian orSiamese Pholas. Most authors agree that alongthe back, from the umbo there is a very thin,narrow plate which cov,ers the suture, wherethe two shells meet. A plate of equalconstruction is also attached to the oppositeside under the ventral part of the mollusc. Thisalone was a sufficient characteristic to separatethe pholads from the bivalves. But the fact thatthese small shells immediately fall off and arelost, when the animal dies, makes it impossibleto, obtain any certainty from these, since, inaddition, the two big shells also fall apart,because they have no locking tooth by whichthey are kept together, like other bivalvespecies; for this reason the pholads are so rarein collections, since the only way to keep themintact is to put them into distilled spirits assoon as they are taken out of the sea, and whilethe animal is still alive. In addition to thedifferent accessory shells, the pholads have.many peculiar traits, which distinguish themfrom the bivalves. With the exception of theIcelandic Pholas crispa,'all pholads are thin andbrittle, in addition white and transparent, butmostly the East Indian ones, and even thelargest, namely Pholas costatus from Virginia,in which everything which is excavated anddepressed on the inside, is raised and elevatedon the outside. In the greatest number ofpholads the margin of the shell, at the lowerand thickest end of the mussel, is reflected likea seam so as to cover the umbones. Also theshells, especially at the lower and thickest end,are, on the outside, set with ribs running


transversally, which again are set with sharpscales like pointed nails; moreover, the shellis streaked in a peculiar way. This formation .of the shell, which resembles a file or a rasp,was not given to the pholad only that it shouldlook nice, but is quite indispensable to theanimal, because, notwithstanding its ratherslow, but continuous rotation it therebyexpands and enlarges its house. Finally, thepholad has another noteworthy trait in itsshell, which may serve as an infalliblecharacteristic of the whole genus. This trait isan excavated, round, outward curved tooth,which takes its origin from the inside frombelow the umbo of each shell, and in lengthrepresents more than one-third of the breadthof the tooth. This is no true interlocking tooth,but presumably serves the animal to attachitself to this part of the shell, since it is notprovided with two strong tendons, like theBivalves, but - as it appears - has only got aweak muscle with which to connect its two

.shells. Every pholad, of whatever shape, orfrom whatever part of the world, whetherlarge or small, always has this tooth as apeculiar trait.

Not all pholad shells are open at both ends,which some authors would reckon to thecharacteristics; for the East Indian ones areopen only at the anterior narrow end, wherethe animal extends its siphon; the thick end ofthe shell below is completely closed. The sameholds good of the wood pholad; however allpholads from European waters gape at bothends.

What cbuld be said about the animal itself,includes the following: a tough~, fleshyexpanded membrane closely encases theinternal side of the shells, issuing at theumbones of the large shells, where it connectsthese as well as the smaller ones with eachother, filling the space where the shells do notfit into each other. The animal itself is enclosedby a strong membrane, which - as in othershells - is usually called its mantle, in whichthe animal lies, is open at both ends and issimilar to a funnel. Through the anterior andnarrower part of the shell the animal extends

a fleshy siphon, which sometimes may be sixinches long. It is divided into two canals,which I already have mentioned several times,of which one canal is larger than the other is.At the extreme ends both these tubes areprovided with something like teeth. Due to thegreat difference of the pholaa shell, it may besupposed that the animals inhabiting it, mayalso be different in some respects.

We find in the sea so many bored woodpieces and stones which appear to beinhabited by bivalve species. The stones nowseem to be a type of shale, now a kind ofhardened clay. The wood is certainly roots ofthe trees growing near the beach. I howeverallow myself to point out that this work shouldnot be ascribed to the pholads, for these driftobjects in the sea probably do not derive fromthese.

I have previously shown that a great numberof bivalve species, like the pholads, usuallybore into foreign objects, and these make mesuggest that they made this boring. HoweverI do consider it probable that also other marineworms, which are not provided with hardshells, might be able to bore the innumerableholes, which are found in so many shells andother sea products without just inhabitingthem.

Now lovers of conchology may expect thatI should also state the species, which representthe genus Pholas, and the number, which Ipossess of them. I intend here to follow thesame procedure as in the preceding genus,namely: for the few which occur in Linne Ishall retain his designations, since the aregenerally known, and shall only ad~somenotes; the new species I shall however describein more detail. Of citations I have only stateda few, but those which were the best and hadthe most distinct figures.

\

No. 1.Phalas Dactylus.Testa oblonga hine reticulatostriata. Lin. Syst.

Nat. p. 1110. No. 20.Reaumur Mem. de l'Acad. de Science. 1712.

p. 125. PI. 7. fig. 1. 2.


Dargenville Zormophose [sic]. PI. 7. Fig. Q.Pennant Br. Zool. Tom. 4. Tab. 39. Fig. 10.Chemnitz. Tom. 8. Tab. 101. Fig. 859.

Note.The pholads, which are frequently found onthe French coast near Poitou and d'Aunis, andare there used for eating, are similar in allrespects to those, which occur in the Adriaticon the low beach not far from Ancona. Thetwo big shells are distinguished from thosewhich come from the East Indies and Americaby having; at the lower thicker part of the shell,and just opposite to the umbo a roundedincision which, when the two valves meet,forms a heart-shaped opening. Likewise, at theupper edge, from the umbo right to theextreme tip, both shells form between themanother but smaller opening, so that bothanterior ends of the big shells terminate in anarrow rounded point.

The animal itself, which inhabits this pholad,is thus lying quite exposed in the heart-shapedopening, while otherwise in most other speciesnothing of the animal is visible except the longproboscis or siphon. Both valves have on theback, above the umbones, a double umbonalreflection, which covers them completely, butwhich, between themselves, are divided intosmall chambers by thin partitions. Since thepholad shells are not connected with theanimal by any hinge tooth or strong tendonsas in the bivalves, these portioned chambersare useful in the way that with which the twolarge valves are lined inside, and which areinserted between the umbones for connectingthe shells, can attach themselves more easilyto the small canals.

This species generally attains a length of 31/2-in. It has four accessory shells, namely:two placed longitudinally beside each otherabove the umbones, the third is placedimmediately behind the umbo, and the fourth,which is a long very narrow plate, placedlongitudinally and covering the suture, whichis found on the back. They always stick in clayon the coasts of France, England and Ireland.

No.2.Pholas costatus.Testa ovata, costis elevatis striata. Linn. No.

21.Lister Rist. Conchyl. Tab. 434. fig. 277.Gualtieri. Tab. 105. fig. G.Chemnitz. Tom. 8. fig. 863.

Note.This pholad is the largest of its genus, and Ishall still add, the most beautiful. It has 25 or26 narrow elevated ribs; which are densely setwith small hollow scales, all issuing from themiddle and filling the entire mollusc from oneend to the other. Deep and wide furrowsseparate the above-mentioned ribs, on theinside of the mollusc forming smooth roundlyelevated folds, which again make the lowermargin of the shell crenulated: the small scaleswhich adorn the ribs, and are roundly elevatedon the outside, are depressed on the inside.The umbo in both shells is deeply reflected,but is not covered by the suture as in otherpholads. This suture stands firm in a fineposition, straight and erect, without touchingthe umbones, for which reason it obtains anavel depression from the anterior andposterior side. Towards the anterior part of themollusc, where it begins to taper, the umbonalreflection is doubly reflected, then forming afunnel-shaped depression. On the internaledge of the shell and the ridge, just below theumbo, an elevated ridge, equal to a flattenedtooth, is placed obliquely on each shell. Theone does not interlock with theJlther, they justmeet and have a hole in the middle; the curvedteeth, which from the inside appear under theumbones, are very deeply excavated, and atthe extreme end more than one time as broadas at their issue. Although this species doesnot possess the heart-shaped incision like thepreceding one, it is not closed at the lower part,but leave many more interspaces open, whichthe animal must close by its fleshy membrane,covering the joining by its accessory shells. Noauthor can say anything definite about theseaccessory shells. I was already content withobtaining the large shells of both my


specimens, and willingly relinquished thesmall ones. Lister, as the first author to recordthis pholad, states its home to be Virginia. Thelargest of my specimens is 5 1/4 -in. long.

No.3.Pholas Siamensis.Testa oblonga, extremitate crassiore reticulato

muricata, tenuiore laevi. Valvulis accessoriisquatuor inaequalibus.

New collections of the Kongelige DanskeVidenskabers Selskabers Skrivter 3rd part.Pag. 128-138 with a copper.

Chemnitz. Tom. 8. 18th vignette p. 347.

Note.This six-shelled Siamese pholad is the rarestof its kind, due to its four accessory shells. Nextto Phol. Costatus it surpasses all other pholadsin length, since it attains more than four inches.On the other inflated shell, from the broadestend almost to the middle, it is set with elevatedribs longitudinally and transversely, whichribs again are separated into small scales: theremaining narrow part of the shell is quitesmoothThe seam, which covers the umbones, is alsodouble here, and the interspace between theseas in Phol. Dactyl. is partitioned into chambers.But the most peculiar trait in this molluscspecies is the lid below the four accessoryshells, which covers both umbones. It is 11/2-in. long and 10-lin. broad, strongly built,domed above and excavated below, of theshape of a Patella, which it also resembles.Under this lid lies the other accessory shell,which in rarity is not inferior to the former.This shell is elongated square, and incomparison with the former, only small, butrather strong: on the middle of the margin avery small, narrow shell is lying, which isattached by a ligament. The dorsal seam,where the two large shells are joined, iscovered by the fourth shell, which is long,narrow and thin.This mollusc species together with the animalI described in a paper, which I read before DetKongelige Danske Videnskabers Selskab, in

whose above-mentioned papers it is publishedtogether with a drawing to which I refer thespecialists.

No.4.Pholas candidus.Testa oblonga, undique striis decussatis

muricata. Linn. No. 23. pag. 1111.Gualtieri. Tab. 105. fig. E.Pennant British Zool. Tom. 4. Tab. 39. fig. 11Chemnitz. Tom. 8. fig. 861.

NoteThis pholad shell has much in common withthe two preceding ones. It is likewise whiteand transparent, and the elevated streaks andspines on the inside are depressed in the sameway as in the two preceding species. In thelower part it is more inflated than the lastdescribed.The streaks set with spines rise upward abovethe entire external shell, while in the Siamesepholad they only reach the middle. Theumbonal reflection is single and withoutchambers; it reaches right to the extrememargin of the shell, from there rising upwardabove the umbones, which it only touchesslightly. This species is more rounded at bothends than the last one described. It is from thebeachSlear Tranquebar.

No.5.Pholas explanatus.Testa ovata, reticulato-striata, apice laevi

rotundata, margine anali explanato plano.Solander.

Chemnitz. Tom. 8. fig. 862.

Note.This shell species without any doubt deservesa place of its own among the pholads. Themost peculiar trait is that the umbo occupiesalmost the middle of the shell, it is detachedfrom all sides and appears to be inflated likethe whole shell. The umbonal reflection at thelower and broadest end of the shell is outsidefinely streaked longitudinally, then, at somedistance from the umbo, rises steeply


upwards, and at last touches it only with asmall tip.The projecting streaks which cross the shell,longitudinally and transversally, are ratherblunt as are also the small tubercles with whichthey are furnished, in the depression, on theinternal side, they are however still visible. Inproportion to the breadth and thickness thisspecies is short and somewhat elongate ovalin outline. It is transparent, but not very white.It originates from the coast of Guinea. Itslength twice surpasses the breadth; it isnamely 2 inches and 1 line long, and 1 inch, 1line broad.

No.6.Pholas papyraceus.[new species, illustration 1]Testa ovali oblonga, antice oblique striata, striisremotis denticulatis, medio sulco notata. Solander.

Note.This little three-shelled pholad has an elongateoval shape. From the umbo fine, elevatedstreaks issue transversally over the wholeshell, which at the anterior edge, especiallytowards the lower thickest part are set withpointed spines. Similar streaks run alsolongitudinally, but they only occupy half theshell, reckoned from the lower part. Theumbonal reflection, which is thin and fine, herecovers the umbones like in most pholads. Onthis is placed a third shell, which is long andnarrow, roundly reflected towards the umboand excavated from inside. Inside the shellshave a beautiful lustre, and the streaks andspines on the outside appear very regularlydepressed inside. When both shells are placedupon each other they have a cylindrical figure

Illustration 1. Pholas papyraceus Fig. 4. extractedfrom Plate 1

and are closely joined at the lower thicker end,only at the upper and narrower part are theyopen, where the animal extends its siphon orproboscis with a double canal of a length ofthree-quarts to one inch. On the whole, thisanimal, like all other pholads, is encased in afleshy membrane or mantle, whereby the two

. shells, which are lined herewith, areconnected, and at both ends have only a singleopening. The colour is white, and the shellsare very thin and fragile. A traveler took it outof its holes on the beach near the English Isleof Wight, where it is sitting firmly in the clay.Likewise, it is found stuck in clayey bottomon thebeach on the island of Foehr, situated near theDuchy of Slesvig at the North Sea.

No.7.Pholas striatus.Testa ovata multifariam striata. Linne No. 22.

Note.Since I am not sure that the pholad in mycollection, which I might believe to be LinnePhol. Striatus, is the right one, and Gualt. Fig.F. Tab. 105, which Linne states, appear dubiousto me, I would rather list this pholad in mycollection as a new species and describe itunder the following No.8, until, at the firstopportunity, I can get hold of the true LinneanPholas Striatus.

No.8.Pholas quadrizonatus, [Illustration 2]pyriformis, areis quatuor transversis binislaevibus, binis striatis, alternantibus.

Chemnitz. Tom. 8. fig. 864-66.

Note.Among the different peculiar pholads also thissmall species must call forth Nature lovers'surprise. It is pear-shaped in outline, and, inaddition to the two large shells, it has fouradditional accessory shells. Each surface ofboth large shells has sections, which not onlydiffer from each other mutually but also are


also remarkably separated by oblique lines.Below, at the thick rounded end, towards theextreme sharp margin, a narrow, smooth,white, transparent area becomes separatedfrom the upper part, obliquely to the outlineof the shell, as shown in the drawing Fig. 1.aa. The above-mentioned upper part bb is veryfinely streaked longitudinally andtransversely, and has an opaque dull colour.The third compartment is the narrowest,somewhat depressed, very finely streakedtransversely, and differing from the others bythe colour, which is somewhat transparent.Litr. c.c. The fourth section is found at theanterior pointed end of the shell Litr. d.d.,issuing, like the second and third from theumbo. From above to below it is transverselyseparated into scales, which again arebeautifully streaked longitudinally. The colouris like chalk, without lustre. The four accessoryshells are quite different in this little pholadthan in all others of the genus. They lie twoand two together on the back of the big shellsand meet in the middle of the umbones; thetwo facing the thicker parts of the shell Litr. I.

are much shorter than the two others Litr. f,which are directed forward. They are notplaced close to the big shells, but on each sidehave a common band or ridge, Fig. 2 h, whichkeeps them fixed to the umbo, which isexpanded towards the inside of the shell likein Bivalves, so that they do not easily fall offand are lost. - The tooth, which in all otherpholads appears from the inside below theumbo, in this one issues from the abovementioned inward expanded umbonalreflection, Fig. 2 g.g.; it is rounded, taperinganteriorly and reflected both inward andoutward. Inside the shells arewhite and smooth. Both my specimens I gotfrom the East Indies. Fig. 3 is the natural size.

No.9.Phalas pusillus.Testa oblonga rotundata arcuato-striata. Lin.

No. 24.Beschaftigungen der Berliner Gesellschaft

Naturforschender Freunde. 4th vol. Tab. 5.p.167.

Chemnitz Tom. 8. fig. 867-71.

No. 10.Phalas crispatus.Testa ovali, hine obtusiore crispato-striata,

cardinis dente curvo. Linn. No. 25.Pennant. Brit. Zool. Tom. 4. Tab. 40. fig. 12.Lister. Tab. Anat. in Append. Tab. 19. fig. 3.Chemnitz. Tome. 8. fig. 872-74.

Note.This is the pholad about which I have alreadysaid it is distinguished from all the otherspecies of the genus by its thick, strong shelland by its lesser transparency. In outline it is atrue oval, since, in proportion to its breadth itis extremely short.

Note.Since - as mentioned above - in a paper in theBerlinske Selskabs Skrivter - I described in

J detail and also portrayed this five-shelledwood pholaq, it would be futile here to repeatthis description.

a.

Illustration 2. Pholas quadrizonatus Figs. 1-3.extracted from Plate 1


At the lover and thicker end both valves, as inPha!' Dactyl., are incised and form a heartshaped opening. Outside the shell is roundlydomed in this place, and longitudinallytraversed by elevated hollowed crenulatedstreaks, which again, from the umbodownward, are crossed by depressed furrows.Towards the tip, these streaks, which are setwith scales, closely approach each other,thereby looking like sharp spines. Theremaining part of the shell, towards theanterior end, is mainly smooth. Through themiddle of the shell a depressed furrow isrunning transversally, dividing this into twoequally large parts. In young shells this furrow,on the inside, is highly elevated, and towardsthe extreme edge, reckoned from the anteriorpart of the shell, two big muscle scars areplaced, as seen in the bivalved species. In otherpholads none are seen, or there are only veryfaint traces of them. The umbonal reflection isstrong, and not only covers the umbones, butalso part of the shell proper. The curved teeth,which from the inside project below theumbones, are very long and flattened. In thismollusc species I saw the supposed traitconfirmed, namely that these teeth are onlyused to attach the animal to its shell. Abovethe umbo an elongate oval lid is situated,which represents the third shell in thispholad;more shells are not known. Since this specieshas very short shells, a large part of the animalis uncovered anteriorly, but this deficiency iscompensated by a folded curly membrane, inthe middle of the part projecting from theshells another cylindrical tube covered by asmooth white skin appears, which is dividedinto two canals. On the other broader side,where the mantle of the animal covers theshells inside and surrounds the animal, thismantle, in the middle, has an elongaterounded orifice of width like a small spring,through which a rounded cylindrical bodyappears. - It belongs to Norway and Iceland,and is generally also frequent in England.FrO:lTI;Norway I have specimens of 3 1/4-in.lengthand2-in. breadth.

',' ...'~ ,- '. ..' .

No. 11.Phalas crenulatus.Testa ovata ubique reticulato-striata, antice

superne hians, crenulata, cardine protrusotruncato.

Solander.Pennant Brit. Zoo1. Tab. 4c. fig. 13.

NoteThis small Phalas has great similarity to thepreceding Phal. crispatus, and at a fleetingglance it could easily be taken for a young notyet full-grown specimen of the latter, but bycloser examination, it is soon seen that it is adistinct species. It is true that it has the heartshaped incision in common with both thePholad species Dactyl. and Crispatus, howeverit is not a short oval as the latter, but elongatenarrow in outline. On the entire externalsurface of the shell the crenulate elevatedstreaks described in Phal. Crispatus run,following their incisions, but, at the lower partof the shell- as far as the heart-shaped incisionis concerned - they are much stronger and, atthe depressed furrows, which run downwardfrom the umbo, form numerous spine-shapedscales which look like teeth at the lowermargin.This small species has not - like crispatus - thedepressed furrow, which divides the shell intotwo parts as in that one.The umbo is narrow, in addition somewhatimpressed and also is not covered by theumbonal reflection. On the inside, where thehinge is found in the Bivalves, two roundedtubercles touch each other. Below these thetwo curved, flattened teeth appear. Not farfrom the internal margin, at the narrow sideof the shell, a peculiar oval muscle scarappears.

Its length is 1 inch and its breadth 7 lines.According to English authors, it never exceedsthis size. It is from the Isle of Wight and wastaken from a clayey bottom on the beach atebb tide; it is however also found on severalEnglish coasts.


On the genus Teredo Linnaei.

Although this genus is closely connected withthe preceding Pholas I am neverthelessjustified, due to the difference in theconfigurations of the animal, as well as'of thestone-shelled parts, to let the genus Teredofollow immediately after Pholas, instead ofuniting it with this genus, as did Adanson andMuller.

It is highly probable that Linne never hadthe opportunity to see his Teredo, otherwise hewould not only have given us a quite differentdescription of it; he also would not haveseparated it so far from the shells in his system,but in all probability would have placed it asa fourth class among the multi-valved shells.Nor did he state more than a single species,though there are still more, which I shalldescribe below.

No. 12.Teredo navalis,remis pinnatix.

Note.The animal of Teredo (ship worm), like thepholads, has no tool or foot for creeping suchas have other mollusc species, and thereforeneeds a house, where it can be safe from alldangers; it therefore seeks, in company withthe five-shelled wood pholads (pholas pusillusNo.9) to excavate its burrow in the bottom ofships and in poles near the beach, in order tofind a safe place. The hard-shelled parts ofTeredo consist of five parts, which are different.The first and largest part may be the longcylinder or tube, which encloses the animaltogether with thee remaining shells. It is verythin, but still unusually hard. It is open at bothends, and somewhat wider at the lower thanat the upper end. The following two parts arethe shells, which are attached to the animalbya fleshy membrane like in the pholads, theyhave the same shape, only with the differencethat they are much shorter, and perhaps theshortest of all mollusc species.Without an exact drawing of this shipworm,

even the most perfect and laboriouslyprepared description will be insufficient to beunderstood by the reader; I can therefore, bymeans of this drawing, be briefer than I couldotherwise be.

When both shells are joined so that theyoccupy their natural position together with theanimal, they constitute a circle Fig. 1. Tab. 2.Just above, where the umbones are situated,and where the shell is broadest, they meet ona rounded elevation, the same occurs below,where the shell is narrow, they are adjoinedon equally formed tubercles Figs. 1. 2. a.a. Theanterior side Fig. 1 and 3 Litr, b.b. are finelycorrugated like a file, which is used by theanimal as a boring tool (and which Linneregarded as the maxillae of the animal). Theposterior and broadest part, which has asmooth shell Fig. 3., Litr. c, together with thetwo projecting and reflected wing-formedlobes, which issue from the umbones Fig. 2and 3 Litr. d.d., become united with the animalby a fleshy membrane, and this completelycloses the gaps between the shells. The curvedteeth also appear from the inside beneath theumbos, as in the pholads; they are very longand curved, following the shell, behind theroot flattened and narrow, but anteriorlybecome somewhat broader and hollowed likea spoon, and likewise serve to establish a firmconnection with the animal. - The two smallestand last, hard-shelled, parts have a toolresembling a quill Fig. A in order to close theanterior orifice of the animal.

This tool is 1 inch long, of which the stalkrepresents one half, and the other half, whichis flattened on one side and rounded on theother, consists of 12 small cups, one placedinside the other, gradually decreasing in size,at last ending in a point. I shall give an accountof the animal after first having described thefollowing two speCies.

No. 13.Teredo norvegicus,remis ovatis.

Adanson. PI. 19. Taret.


Note.The difference of this species lies in the fourhard-shelled parts. The two largest shells,which are attached to the lower part of theanimal and represent a circle Fig. A. have otherproportions than the preceding ones. This part,which served the animal as a boring tool, andtherefore is finely corrugated as a file, is hereconsiderably broader Fig. 5 e, and the smoothposterior part is therefore so much smaller F.The wing-shaped lobes are small, placedforward and not reflected backward, and forthat reason the gaps on both sides become somuch smaller. The teeth of this Teredo have acompletely different shape, they are exactlysimilar to the expanded wing of a bird. At theroot they are narrow, incised and insertedanteriorly, right below the umbo, they arebroad and flattened like the blade of a knife,thin as paper, roundly reflected round theshells, and represents two-thirds of the lengthof these Fig. 6 Litr. g. The two smallest hardshelled parts of this shipworm are two smallplates, of the shape of an oar, each with a smallstalk Fig. 8. On one side they are excavatedwith an erect narrow margin towards the stalk,on the other side roundly reflected.

In the Frederiksvaerns harbour in Norway,where the king's warships are lying, theseshipworms had bored into these and even intooak, and also into a ship which was lying threemonths in Taarningen harbour near Tronheim.This species is by far not so common as thepreceding one.

No. 14.Teredo batavus,remis furcatis.Neue Beschreibung des hollandischen See

oder Phalwurms, 1733. Tab. 1. fig. 7. Tab. 3.fig. 18.

Note.The third species of Teredo is finally the Dutchone. It was the woodworms which in 1731terrified whole Holland since, by penetratingpoles of the dams and dikes, in many placeswhich were built on a kind of poles, gave rise

to great alarm. The two roundly curved shells,with a very slight difference, have the sameshape as the preceding one, but the twosmaller ones have a quite different shape. Thepreceding ones had the shape of an oar blade,but these are roundly incised from the anteriorend, and have a point on each side like a fork;they are domed on one surface, and excavatedon the other Fig. C. Of this kind of shipwormI have never seen more than a single oneamong thousands from our ships.

The animal has a very soft body, and it isseldom found otherwise than dissolved intomucus. Only the hard-shelled parts are foundintact lying round each other in their burrow.Like Solen, this wood worm has a thinmembranous siphon, which by muscles isattached to both ends of the hard-shelledcylinder; in this so-called mantle ormembranous Siphon the animal is suspendedFig. 7. Due to the transparency the stomach isvisible in the animal a. b. It has only a singleaperture, through which the animal can obtainnourishment and have access to the sea water;this aperture is found at the anterior andnarrowest end c.c., where a strong musclesecures the animal to the cylindrical siphon,and where the two small shells d.d. areconnected. From the middle its double tubeprojects in all pholads c. When the animalwithdraws this short double tube, the small,hard-shelled parts d.d. tightly close the house.- Here naturalists have no other possiblesupposition as to how this animal could forceits way into the wood and excavate its burrow,where, from the outside no other trace wasvisible than a small hole of the size of apinhead, than this; that the young of Teredo hadpenetrated through the pores into the wood,which furthermore had been dilated by the seawater and soaked, and there, by means of itsnatural appliances, by incessant turning androtating, excavated its burrow, where theywere forever enclosed, and by means of asiphon, provided with two canals, through onesmall opening, could draw air andnourishment, and through the other get rid ofthe superfluous products.


T~. T~.II.

A /

Frj.2. F{j.2. Fi;;.3.

b b d

a

a

F-{J.4. Frj.6'. Fzj..5.B,

~ ¥c "

DD

0 t ~ ~7,j~~

Illustration 3. Spenglers Plate II, showing teredinids referred to in the text.

No. 15.Teredo nucivoyus,rernis sernipectinaris.Naturforscher, 13 Band p. 53. Tab. 1. 2.

Note.Another kind of Teredo I discovered in stony,worn tubes, which bore into a kind of nuts,which are floating in the East Indian Sea; these,


Index: the species of Pholas and Teredodescribed by Spengler (1792)

REFERENCES, see this volume 25(2):529-538.

together with the animal I have ordered inalcohol from Tranquebar, and have been ableto give a clear description of the animal as wellas of the hard-shelled house and the fruit inwhich it took up its quarters. Tab. 2. Fig. D.

In a detailed paper, with two copper plates,published in the 13th volume of"Naturforskeren" p. 53, Tab. 1 & 2, I alreadydid that, and it would therefore be superfluousto repeat it. In the 20th volume ofNaturforskeren p.1 I have inserted asystematic description by Dr. Koenig of thisrare fruit at myrequest.

All the shells described in this paper areoriginals from my collection.

Explanation of Flates 1. and 2.Plate 1. PholasPholas quadrizonatus Fig. 1-3.Fig. 4. Pholas papyraceus.Plate 2. TeredoFig. 1-7, and Litr. A. B. C. D.

Pholascandidus Linnecostatus Linnecrenulatus Solandercrispatus Linnedactylus Linneexplanatus Chemnitzpapyraceus [new species]pusillus Linnequadrizonatus Chemnitz.siamensis Spenglerstriatus Linne

Teredobatavus no author statednavalis Linnenorvegicus Adansonnucivorus Spengler

No.4.No.2.No. 11.No. 10No.1.No.5.No.6.No.9.No.8.No.3.No.7.

No. 14.No. 12.No. 13.No. 15.

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