Botanica Marina 2014; 57(4): 243–250

Paul C. Silvaa, Francisco F. Pedroche, Max E. Chacana and Kathy Ann Miller*

Validation of the names of two new species of Codium (Chlorophyta, Bryopsidales) from Isla Guadalupe and Rocas Alijos, Pacific Mexico and the southern California Channel Islands, with some remarks on insular endemism

Abstract: The names Codium schmiederi and Codium dawsonii are validated by the provision of designated types. The species to which the invalidly published name C. schmiederi applies is known only from Isla Guadalupe and Rocas Alijos, Baja California, Mexico. The history of phycological exploration of these two remote localities is detailed. The species to which the invalidly published name C. dawsonii applies is found in those two locali-ties as well as on coastal islands of Baja California and southern California. It is seldom found on the mainland. Codium hubbsii, originally described from Islas San Ben-ito, has a distribution similar to that of C. dawsonii, but occurs more often on the mainland. The distributions of these three species constitute a pattern of insular endemism.

Keywords: California Channel Islands; Codium dawsonii; Codium hubbsii; Codium schmiederi; Isla Guadalupe; Rocas Alijos.

DOI 10.1515/bot-2014-0024Received 28 April, 2014; accepted 13 June, 2014; online first 11 July, 2014

Introduction

Phycological exploration of Isla Guadalupe and Rocas Alijos, Pacific Mexico, has revealed striking similarities between the two marine floras, including the presence at both of these remote sites of two new species of Codium. Descriptions of the sites and the history of their phycologi-cal exploration follow.

Isla Guadalupe

Isla Guadalupe (28.8833° N, 118.3000° W) is a volcanic oceanic island 260 km west of the peninsula of Baja California. It is about 37 km long and 12 km wide, with a maximum height of 1295 m. An excellent account of the island, including its daunting physical features and history of exploration (and exploitation) is provided in detail by Moran (1996). The first naturalist to introduce to science the flora of this remote and inhospitable island was Edward Palmer (1831–1911), a professional collector with a special interest in plants. According to his biog-rapher (McVaugh 1956), Palmer was eager to collect the plants before they were destroyed by goats, which had been put on the island for commercial purposes. After he visited the island in 1875 (February 1–May 16), his col-lections were arranged systematically and distributed by the Gray Herbarium at Harvard under the supervision of Sereno Watson, its curator and chief supporter of Palm-er’s venture. Eleven sets were distributed, including one to Daniel C. Eaton of Yale University. Although the list of Palmer’s Guadalupe collections published by Watson (1876) is devoid of algae, Farlow (1877) stated that several interesting forms of marine algae had been collected, but he provided no details. Three of these have entered scien-tific literature, as follows.

aOur beloved mentor Paul Silva died prior to the publication of this article.*Corresponding author: Kathy Ann Miller, University Herbarium, University of California, Berkeley, CA 95720, USA, e-mail: kathyannmiller@berkeley.eduPaul C. Silva and Max E. Chacana: University Herbarium, University of California, Berkeley, CA 95720, USAFrancisco F. Pedroche: University Herbarium, University of California, Berkeley, CA 95720, USA; and Departamento de Ciencias Ambientales, Universidad Autónoma Metropolitana-Lerma, Lerma de Villada, Estado de México 52007, Mexico

Unauthenticated | 10.248.254.158Download Date | 8/20/14 5:02 PM

244      P.C. Silva et al.: New Codium species from southern California and Pacific Mexico

Material of a Sargassum collected by Palmer was dis-tributed under the name Sargassum piluliferum (Turner) C. Agardh as no. 102 in Exsiccatae Americae Borealis (Farlow et  al. 1878). In his monograph of Sargassum, Grunow (1915) recognized this material as representative of an undescribed species, which he named Sargassum palmeri. During the hiatus of communication in World War I, Setchell and Gardner (in Gardner 1917) indepen-dently came to the same conclusion, proposing the name Sargassum dissectifolium, which they later (Setchell and Gardner 1925) abandoned in favor of S. palmeri.

Material of a Codium collected by Palmer remained undetermined in various herbaria. A duplicate of this Codium in the Daniel Cady Eaton Herbarium at Yale was sent to Setchell by F.S. Collins (UC 207177). Setchell and Gardner (1920) referred it to Codium latum Suringar, a foliose species originally described from Japan. Later, Setchell annotated the sheet “ =  C. Palmeri Setchell sp. nov. May 1925”. Setchell and Gardner (1930) reconsidered Palmer’s collection of Codium, writing:

“We feel inclined to separate the Guadalupe plant and dedicate it to its collector, but in view of the uncertainty as to the situation among the Japanese species, we retain our previous disposition of it...” The name Codium palmeri was published by Dawson (1945). Silva (1962) treated the taxon as a subspecies of C. latum, a treatment maintained by Pedroche (1998) and Pedroche et al. (2002, 2005).

A single specimen of a Microdictyon collected by Palmer was observed in the Farlow Herbarium by Collins (1909, p. 366), who identified it as Microdictyon agardhi-anum Decaisne. In his monographic study of Microdic-tyon, Setchell (1925, pp. 104, 106; 1929, p. 535, figs. 57–61) recognized this specimen as representative of an unde-scribed species, which he named Microdictyon palmeri.

Following Palmer’s lead, several naturalists and botanists visited Isla Guadalupe; significant collections of algae were first obtained in 1925, by Herbert L. Mason on the California Academy of Sciences Expedition to the Revillagigedo Islands. En route to the Revillagigedo Archipelago, the expedition spent 4  days at Isla Guada-lupe (April 19–22, 1925), enabling Mason to collect a suf-ficient variety of seaweeds to supply Setchell and Gardner (1930) with type specimens of 24 new species and varie-ties. Mason’s collections also included representatives of Codium fragile (Suringar) Hariot, a species originally described from Japan but widespread in cold temper-ate waters everywhere, and Codium simulans Setchell et Gardner, originally described from the Gulf of California. Collections of algae were made on Isla Guadalupe by John Thomas Howell on the Templeton Crocker Expedition of the California Academy of Sciences in 1932 (the “Zaca

Expedition” in reference to the name of the yacht), but only novelties were published (Setchell and Gardner 1937).

The Great Depression and World War II stopped further exploration. At the end of the war, several minor expeditions were mounted by the San Diego Natural History Museum and the Scripps Institution of Oceanog-raphy. Carl Hubbs, the eminent ichthyologist at Scripps, began sending seaweeds that had been collected inci-dentally to E. Yale Dawson, then at the Allan Hancock Foundation at the University of Southern California in Los Angeles. Dawson, himself, was able to visit the island in 1948, returning with several collections of Codium, which he sent to P.C. Silva.

Silva soon had an opportunity to see the Isla Guada-lupe Codium in situ. He served as phycologist on a series of expeditions on board the RV Orca, sponsored by the Joseph W. Sefton Foundation of San Diego. One such trip, in January 1950, had as its goal the exploration of the Mexican Pacific coastal islands from Islas Los Coro-nados to Islas San Benito and, thence, to Isla Guadalupe. The terrain of the latter island is so rugged and the cliffs so daunting that only a few sites are suitable for inter-tidal collecting, and these are most readily accessible by jumping from a small boat. Silva landed on a narrow plat-form with deep tide pools at West Anchorage. He discov-ered that he was in a Codium garden, with six species at his fingertips. Back on board the Orca, he examined the anatomy of the Codium collections and found that there were two obviously undescribed species in addition to C. palmeri, C. fragile, C. simulans, and an adherent form soon to be described as Codium hubbsii Dawson (1950). The two undescribed species were tentatively named Codium dawsonii and Codium seftoniii.

By comparing the list of Palmer’s collections of sper-matophytes with the contemporaneously known distri-bution of these species, Moran (1996, p. 45) inferred that Palmer did not reach the south end of the island, which is the location of Melpomene Cove, an excellent collecting site. Rather, he probably got as far south as West Anchor-age so that it is likely that Silva was standing on the same platform where Palmer collected C. palmeri.

The collections made by Dawson and Silva were put aside, while other regional monographs were being prepared. They were eventually entrusted to Pedroche, whose doctoral thesis on the Codium of Pacific Mexico was published in 1998 (Pedroche 1998). In 2000, Pedroche served as phycologist on a binational expedition to Isla Guadalupe sponsored by the San Diego Natural History Museum. Pedroche’s thesis was published as a mono-graph co-authored by Silva and Chacana (Pedroche et al. 2002).

Unauthenticated | 10.248.254.158Download Date | 8/20/14 5:02 PM

P.C. Silva et al.: New Codium species from southern California and Pacific Mexico      245

Rocas Alijos

Rocas Alijos (24.9586° N, 115.7497° W) are the remnants of an ancient volcanic island lying about 550 km southeast of Isla Guadalupe and 320 km west of the Baja California peninsula at a latitude of 25° N. There are three main emer-gent pinnacles, the tallest of which is 34.5 m high. The first scientific expedition to Rocas Alijos was sponsored by the California Academy of Sciences (Hanna 1926). En route from Isla Guadalupe to Isla Clarión, the U.S. mine sweeper Ortolan lay at Rocas Alijos the morning of April 24, 1925. Dynamiting for fish resulted in a few seaweeds, but their fate is unknown. Dawson (1957) summarized subsequent algal exploration of Rocas Alijos, pointing out that the first comprehensive collections were made by Conrad Limbaugh, who SCUBA dived during an expedition spon-sored by the Scripps Institution of Oceanography. Among Limbaugh’s collections was a specimen of Codium hubbsii (misidentified by Dawson as Codium setchellii).

In 1990, the Cordell Expeditions, a nonprofit organi-zation founded by Robert W. Schmieder and based in Walnut Creek, California, mounted a full-scale operation with a scientific crew of 30. Robert A. Rasmussen (Hum-boldt State University, Arcata, California) was responsi-ble for collecting or supervising the collections of marine algae. A second Cordell Expedition visited Rocas Alijos in November 1993, with 12 scientists. An account of these collections is given by Silva et al. (1996), who concluded that the marine flora may be considered an impoverished selection of the flora of Isla Guadalupe. Two previously undescribed species of Codium, Codium dawsonii and Codium schmiederi, were found to occur at both locali-ties, in addition to C. hubbsii. While C. dawsonii and C. schmiederi have been cited (Silva et  al. 1996, Pedroche 1998, Pedroche et  al. 2002, 2005), their names have not yet been validly published. The purpose of the present account is to validate these names and to discuss the phy-togeographic relationships of Codium as represented at Isla Guadalupe, Rocas Alijos, and coastal islands of Cali-fornia and Baja California, Mexico.

Systematic treatment

Codium schmiederi P.C. Silva, F.F. Pedroche, M.E. Chacana (Figures 1 and 2)

Thallus prostrate, pulvinate, with erect or repent portions branched irregularly or subdichotomously (Figure  1). Branches cylindrical or compressed, 3–12  mm wide at

Figure 1 Holotype of Codium schmiederi (UC 1718021).

interdichotomies, 20 mm broad at dichotomies, intertwin-ing, anastomosing, attached to substrate here and there; pulvinate portion 3–5 mm thick, spongy, adhering loosely to the substrate. Thallus easy to dissect, mature utricles cylindrical, (900–) 1000–1300 (–1800) μm long, (89–) 110–190 (–390) μm in diameter. Utricles from adherent portion of thallus showing much reduced sympodial growth, resulting in groups of utricles, most with two septa, one for each medullary filament (Figure 2A). Utricles of the branched portion of the thallus showing less compact growth (Figure 2B). Apices truncate or slightly rounded with thin walls (no more than 2–4 μm in thickness). Hairs (or hair scars) common in zone 110–280 μm below apex. Medullary filaments 30–60 μm diameter. Gametangia fusiform or lanceolate, (150–) 210–300 (–350) μm long, (45–) 60–90 (–120) μm diameter, several per utricle borne on cylindrical pedicel 15–30 μm long in zone 330–540 μm below apex.

Holotype

Isla Guadalupe, Baja California, Mexico, on shore, 2.5 miles N of South Bluff, E.Y. Dawson 8518, 20.xii.1949 (UC 1718021). Isotype at US (USNM 230805) (Figure 1).

UC specimens and label information may be viewed by entering the collection number at: //ucjeps.cspace.berkeley.edu/ucjeps_project/public/publicsearch/.

Unauthenticated | 10.248.254.158Download Date | 8/20/14 5:02 PM

246      P.C. Silva et al.: New Codium species from southern California and Pacific Mexico

A B

Figure 2 Utricles of Codium schmiederi (UC 1718021). Scale bar = 750 μm. (A) Utricles from prostrate portion. Utricles with much reduced sympodial growth, resulting in small groups in which interutricular filaments are eliminated. (B) Utricles from upright axes. Primary utricles produce additional utricles by emitting basally a filament that grows periclinally, enlarging to form a new utricle. A plug (arrows) is always formed at or very close to the point of origin of the filament.

Specimens examined

Isla Guadalupe: UC 1718024, AHFH 79209 in UC (UC 1831543), UC 1718018, UC 1718019, UC 1718020, AHFH 72024 in UC (UC 1831545). Rocas Alijos: UC 1946216, UC 1946217.

Codium schmiederi is dimorphic in habit, with a prostrate base from which upright or repent axes arise. The utricles are also dimorphic, differing in basal and upright portions (Figure 2A, B). This morphological and anatomical dimorphism is unique among known species of Codium.

In Codium, all primary utricles are formed by enlarge-ment of deflected apices of sympodially growing fila-ments. In most species, the development of secondary utricles follows one of two paths. In erect dichotomously branched thalli, primary utricles produce additional utricles by emitting basally a filament that grows peri-clinally, enlarging terminally, and deflecting anticlinally to form a new utricle. A plug is always formed at or very close to the point of origin of the filament. (For exam-ples, see Silva and Womersley 1956, figs. 8–16; Silva 1959, figs. 10–21.)

In C. schmiederi, by contrast, the adherent portion of the thallus, which initially resembles a thallus of Codium hubbsii, does not produce “families” of utricles typical of adherent species. Instead, small groups of utricles result from greatly reduced sympodial growth in which interutricular filaments are eliminated. Perversely, the

intertwining branches produce small groups of utricles resembling families typical of adherent species.

The pattern of utricle formation described above as being typical of Codium has many exceptions, depending on the length of the interutricular filament. The pattern most closely similar to that of C. schmiederi is that of Codium coralloides (Kützing) P.C. Silva. In that species, however, the branches are rudimentary. In Codium pel-liculare P.C. Silva (1959), in which the thallus is mem-braniform, secondary utricles bud off the lower or middle portion of an existing utricle, but most do not develop rhizoids. In Codium picturatum F.F. Pedroche et P.C. Silva (1996), which has an extremely thin adherent thallus with a tightly woven medulla, some interutricular filaments are so short that clusters of secondary utricles are formed. In some parts of the thallus, the distribution of second-ary utricles, interutricular filaments, and plugs is chaotic (Pedroche and Silva 1996, figs. 3, 4).

Previous records: as C. schmiederi Silva ined. in Schmieder (1996: 235); as C. schmiederi Silva, Pedroche et Chacana ined. in Pedroche et  al. (2002: 30, figs. 24–28), Pedroche et al. (2005: 76).

In 1952, after returning from an expedition to islands off the coast of Baja California on board the RV Orca, Silva undertook a study of the collections of Codium and intended to name this species Codium seftonii in honor of Joseph W. Sefton, Jr., a San Diego banker and owner of the ship. Prior to the publication of this species, however, Mr.

Unauthenticated | 10.248.254.158Download Date | 8/20/14 5:02 PM

P.C. Silva et al.: New Codium species from southern California and Pacific Mexico      247

Sefton died. The intended honor was transferred to Robert W. Schmieder, the remarkably enterprising explorer who organized the expedition to Rocas Alijos.

Codium dawsonii P.C. Silva, F.F. Pedroche, M.E. Chacana et K.A. Miller (Figures 3 and 4)

Thallus erect, profusely branched to 10 orders, delicate (Figure 3). Branching usually dichotomous or subdichot-omous, but often irregular, giving monopodial aspect to thallus. Branches cylindrical to compressed, especially at the dichotomies and apices, 4 (–5) mm diameter at base, 1.5–2  mm diameter distally, to 13 (–20) cm high. Thallus attached to substrate (rocks or shells) by discoid holdfast. Color olive green to grass green. Thallus dissecting out into individual utricles. Utricles claviform or campanu-late, slightly constricted below the apex, (69–) 100–170 (–200) μm diameter, (370–) 400–500 (–580) μm long in upper portion of thallus, (40–) 60–90 (–110) μm diame-ter basally. Apices of utricles truncate or rounded, apical wall slightly thickened (to 13 μm thick). Hairs or hair scars borne in zone 45–100 μm below apex of utricle. Medullary filaments 20–30 μm diameter (Figure 4). Gametangia lan-ceolate or fusiform, (58–) 62–75 (–85) μm diameter, (140–)

Figure 3 Holotype of Codium dawsonii (UC 1718035). Figure 4 Utricles of Codium dawsonii (UC 1718035). Scale bar = 750 μm.

160–190 (–210) μm long, borne singly on short pedicel in zone 200–300 μm below apex of utricle.

Holotype: Mosquito Cove, San Clemente Island, Cali-fornia, on shallow boulders and reefs with dense algal cover, 6–9 m depth, K.A. Miller SC V-012-88, 22.v.1988 (UC 1718035) (Figure 3).

Specimens examined (north to south)

Channel Islands, CaliforniaSanta Cruz Island: UC1612968, UC1574488, UC1574797, UC1574793, UC1996200. Anacapa Island: UC1996201. Santa Barbara Island: UC1574796, UC1718036, UC1996198, UC1996199, UC1996197. Santa Catalina Island: UC1574794, UC1819304, UC1985389, UC1883562, UC1819309, UC1985388, UC1985390; UC1985392, UC1985391, UC1883561, UC1996193. San Clemente Island: UC1574789, UC1717994, UC1996196, UC1996195.

Baja California, Mexico (insular)Islas Los Coronados: UC1965988, UC1574387. Isla Guada-lupe: UC1818855, UC1818854, UC1818857, UC1718031.

Baja California, Mexico (mainland)Ten miles west of Punta Malarrimo, Bahía Viscaino: UC1918822.

Previous records: as Codium dawsonii Silva ined. in Goff et al. (1992: 1280); Schmieder (1996: 235); as C. daw-sonii Silva, Pedroche et Chacana ined. in Pedroche et al. (2002: 49, figs. 59, 60), Pedroche et al. (2005: 71).

Unauthenticated | 10.248.254.158Download Date | 8/20/14 5:02 PM

248      P.C. Silva et al.: New Codium species from southern California and Pacific Mexico

Following a preliminary study of C. dawsonii from Isla Guadalupe, Silva (1951) published a monograph of the Codium of California, but failed to recognize the presence of C. dawsonii in the Channel Islands. Instead, he assigned a collection from Santa Cruz Island and one from Santa Catalina Island to Codium cuneatum Setchell et Gardner (1924) a species originally described from the Gulf of Cali-fornia that was merged with Codium simulans Setchell et Gardner (1924) by Pedroche (1998). Silva included in C. cuneatum a disparate array of specimens from southern California and northern Baja California.

In the 1980s, Kathy Ann Miller began making sublitto-ral surveys of the Channel Islands and discovered that C. dawsonii grows abundantly and luxuriantly in the south-ern Channel Islands at depths of 9–12 m. In an attempt to determine whether the Gulf species, C. simulans ( =  C. cuneatum), occurs in California, Miller provided material from the type specimens of all species described by Setch-ell and Gardner (1924) from the Gulf of California to Jeffrey R. Hughey. On the basis of comparison of nucleotide sequences obtained from these specimens, he concluded (pers. comm.) that C. dawsonii is distinct from all species of Codium described from the Gulf of California by Setch-ell and Gardner (1924).

Codium dawsonii can be distinguished from Codium fragile subsp. californium C. Maggs et J. Kelly by its lighter color, shorter internodes, and numerous orders of branching. The compressed dichotomies and apices are diagnostic.

Codium hubbsii E.Y. Dawson

Codium hubbsii E.Y. Dawson 1950: 151, fig. 14. Silva, 1951: 85, pl. 1, text-figs. 3, 6–9. Dawson et al. 1960a: 26. Dawson et  al. 1960b: 5–12. Silva et  al. 1996: 235. Pedroche et  al. 2002: 20, figs. 7–14. Pedroche et al. 2005: 74.

Holotype

Islas San Benito, Baja California: Hubbs 46-205, 18.viii.1946 (AHFH 36930 in UC).

Specimens examined (from north to south)

Channel Islands, CaliforniaSanta Cruz Island: UC1819291. Santa Barbara Island: UC1823623. Santa Catalina Island: UC1819289, UC1823612,

UC1735228, UC1935031, UC1935033, UC1823617. San Clem-ente Island: UC1953502.

San Diego County: UC1953501, UC1953498, UC1953497.

Baja California (insular)Islas Los Coronados: UC1831528, UC1604008, UC1831529, UC1604010. Islas Guadalupe: UC1716828, UC1718017. Rocas Alijos: UC1946214, UC1946215.

Baja California (mainland)Tres Hermanas, Bahía de Todos Santos: growing on rocks in intertidal zone, R. Aguilar-Rosas s.n., 30.x.1982, CMMEX 1000, 2005. Campito, 19 km east of Punta San Eugenio, Bahía Vizcaino: UC1831470. Bahía Asunción: UC1604007.

This species is one of several adherent forms distin-guished from one another by anatomical characters that may seem trivial to the nonspecialist. The differences are, in fact, sufficiently large to suggest that these species con-stitute a distinct phylogenetic group. On the Pacific coast of North America, the only adherent species other than Codium hubbsii is Codium setchellii Gardner (1919: 489, pl. 42: figs. 10, 11; type locality Pacific Grove, California), which is readily distinguished by the lack of hairs or hair scars and by the smooth, unornamented apical walls of the utricles. In contrast, utricles of C. hubbsii frequently bear hairs and have apical walls that are usually at least slightly alveolate.

On the mainland of California, C. setchellii usually grows on the sides of boulders partly buried in sand, in the lowest intertidal zone. The thallus forms a tightly adherent carpet that spreads out in all directions. The advent of SCUBA, however, has led to the discovery of a subtidal adherent Codium that is anatomically indistin-guishable from the intertidal form. According to Dawson et  al. (1960a,b), C. hubbsii and C. setchellii are common inhabitants of kelp beds in Baja California at depths of 9–23 m, where they have the same habit and habitat and are macroscopically indistinguishable.

Whereas C. setchellii survives cold water as far north as Sitka, Alaska, and thrives in upwelling areas in Baja California as far south as Punta Baja (Dawson 1953: 109), C. hubbsii requires a higher optimal temperature. It occurs as far north as the southern Channel Islands of Califor-nia, proceeding southward through the Mexican coastal islands and thence along the coast of Baja California Sur as far as Punta Abreojos. At Isla Guadalupe, C. hubbsii grows both intertidally and subtidally (to depths of 25 m). The attribution of C. setchellii to Isla Guadalupe, Isla Asunción, and other localities south of Punta Baja by

Unauthenticated | 10.248.254.158Download Date | 8/20/14 5:02 PM

P.C. Silva et al.: New Codium species from southern California and Pacific Mexico      249

Pedroche (1998) and Pedroche et al. (2002, 2005) is based on a misidentification of C. hubbsii.

Discussion and conclusionEndemic marine algae are well known for the Juan Fer-nandez, Galapagos, and Hawaiian archipelagos, but they also exist among smaller islands, such as Isla Guadalupe and Rocas Alijos off the Pacific coast of Baja California. Sargassum palmeri Grunow, Stephanocystis neglecta (Setchell et Gardner) S. Draisma, E. Ballesteros, F. Rous-seau, et T. Thibaut and Liagora californica Zeh, which are known only from Isla Guadalupe and the southern Channel Islands, are examples of island endemics in Cali-fornia and northern Baja California, Mexico.

Codium schmiederi is a narrow endemic, found only at Isla Guadalupe and Rocas Alijos. Codium dawsonii is a near island endemic that is common in the southern California Channel Islands but absent from the California mainland. It has been found at one site on the mainland of Baja California, Mexico (Bahía Viscaino); it is very possi-ble that further searches in southern Baja California or the Mexican mainland may discover more specimens of this species. Codium hubbsii also occurs at Isla Guadalupe and Rocas Alijos, as well as the Channel Islands of southern California. It, too, is absent from the southern California mainland, but occurs on the mainland of Baja California southward to Bahía Asunción.

It is not possible to determine the factors that gave rise to the different degrees of endemism exhibited by these species of Codium. They may be the result of evolu-tionary history, a pattern of survival following changes to the mainland coast, evidence of differing dispersal capa-bilities – or a combination of these possibilities.

Acknowledgments: Collections in the California Channel Islands were possible due to the extraordinary generos-ity of the Tatman Foundation’s Channel Islands Research Program (John M. Engle, Jerry and Henri Chomeau, Chris Bungener), who sponsored and operated diving cruises in the R/V Cormorant for the last 35 years. We thank the Editor and reviewers for comments that improved this manuscript.

ReferencesCollins, F.S. 1909. The green algae of North America. Tufts Coll.

Stud., Sci. Ser. 2: 79–480.

Dawson, E.Y. 1945. Notes on Pacific coast marine algae. I. Bull. S. Calif. Acad. Sci. 43: 95–101.

Dawson, E.Y. 1950. Notes on Pacific coast marine algae. IV. Am. J. Bot. 37: 337–344.

Dawson, E.Y. 1953. Resumen de las investigaciones recientes sobre algas marinas de la costa pacífica de México, con una sinopsis de la literatura, sinonimia y distribución de las es pecies descritas. Revista Soc. Mex. Hist. Nat. 13: 97–197.

Dawson, E.Y. 1957. Notes on eastern Pacific insular marine algae. Los Angeles County Mus. Contr. Sci. 8: 8.

Dawson, E.Y., M. Neushul and R.D. Wildman. 1960a. Seaweeds asso-ciated with kelp beds along southern California and northwest-ern Mexico. Pac. Nat. 1(14): 2–81.

Dawson, E.Y., M. Neushul and R.D. Wildman. 1960b. New records of sublittoral marine plants from Pacific Baja California. Pac. Nat. 1(19/20): 3–30.

Farlow, W.G. 1877. On some algae new to the United States. Proc. Am. Acad. Arts 12: 235–245.

Farlow, W.G., C.L. Anderson and D.C. Eaton. 1878. Algae Exsicc. Amer. Bor. Fasc. 3: 101–130.

Gardner, N.L. 1917. New Pacific coast marine algae. I. Univ. Calif. Publ. Bot. 6: 377–416.

Gardner, N.L. 1919. New Pacific coast marine algae. IV. Univ. Calif. Publ. Bot. 6: 487–496.

Goff, L.J., L. Liddle, P.C. Silva, M. Voytek and A.W. Coleman. 1992. Tracing species invasion in Codium, a siphonous green alga, using molecular tools. Am. J. Bot. 79: 1279–1285.

Grunow, A. 1915. Additamenta ad cognitionem Sargassorum. Verh. K.K. Zool-Bot. Ges. Wien 65: 329–448.

Hanna, G.D. 1926. Expedition to the Revillagigedo Islands, Mexico, in 1925. I. General report. Proc. Calif. Acad. Sci., Ser. 4, 15: 1–113.

McVaugh, R. 1956. Edward Palmer, plant explorer of the American West. University of Oklahoma Press, Norman. pp. 430.

Moran, R. 1996. The flora of Guadalupe Island, Mexico. Mem. Calif. Acad. Sci. 19: 190.

Pedroche, F.F. 1998. El género Codium (Chlorophyta) en el Pacífico de México. Universidad Nacional Autónoma de México. Tesis.Doctor en Ciencias (Biología). pp. 129.

Pedroche, F.F. and P.C. Silva. 1996. Codium picturatum sp. nov. (Chlorophyta), una especie ex traordinaria del Pacífico tropical mexicano. Acta Bot. Mex. 35: 1–8.

Pedroche, F.F., P.C. Silva and M.E. Chacana. 2002. El género Codium (Codiaceae, Chlorophyta) en el Pacífico de México. Monogr. Ficol. 2002: 11–74.

Pedroche, F.F., P.C. Silva, L.E. Aguilar Rosas, K.M. Dreckmann and R. Aguilar Rosas. 2005. Catálogo de las algas marinas bentóni-cas del Pacífico de México. I. Chlorophycota. Universidad Autónoma de Baja California, En senada. pp. 135.

Schmieder, R.W. 1996. Rocas Alijos. Scientific results from the Cordell Expedition. Kluwer Academic Publishers, Dordrecht. [Monographiae Biologicae vol. 75]. pp. 481.

Setchell, W.A. 1925. Notes on Microdictyon. Univ. Calif. Publ. Bot. 13: 101–107.

Setchell, W.A. 1929. The genus Microdictyon. Univ. Calif. Publ. Bot. 14: 453–588.

Setchell, W.A. and N.L. Gardner. 1920. The marine algae of the Pacific coast of North America. Part II. Chlorophyceae. Univ. Calif. Publ. Bot. 8: 139–374.

Setchell, W.A. and N.L. Gardner. 1924. Expedition of the California Academy of Sciences to the Gulf of California in

Unauthenticated | 10.248.254.158Download Date | 8/20/14 5:02 PM

250      P.C. Silva et al.: New Codium species from southern California and Pacific Mexico

1921. The marine algae. Proc. Calif. Acad. Sci., Ser. 4, 12: 695–949.

Setchell, W.A. and N.L. Gardner. 1925. The marine algae of the Pacific coast of North America. Part III. Melanophyceae. Univ. Calif. Publ. Bot. 8: 383–898.

Setchell, W.A. and N.L. Gardner. 1930. Marine algae of the Revil-lagigedo Islands Expedition in 1925. Proc. Calif. Acad. Sci., Ser. 4, 19: 109–215.

Setchell, W.A. and N.L. Gardner. 1937. The Templeton Crocker Expedition of the California Academy of Sciences, 1932. No. 31. A preliminary report on the algae. Proc. Calif. Acad. Sci., Ser. 4, 22: 65–98.

Silva, P.C. 1951. The genus Codium in California with observations on the structure of the walls of the utricles. Univ. Calif. Publ. Bot. 25: 79–114.

Silva, P.C. 1959. The genus Codium (Chlorophyta) in South Africa. J. S. Afr. Bot. 25: 103–165.

Silva, P.C. 1962. Comparison of algal floristic patterns in the Pacific with those in the Atlantic and Indian oceans, with special refer-ence to Codium. Proc. Ninth Pacific Sci. Congr. [Bangkok, 1957] 4: 201–216.

Silva, P.C. and H.B.S. Womersley. 1956. The genus Codium (Chloro-phyta) in southern Australia. Aust. J. Bot. 4: 261–289.

Silva, P.C., R.A. Rasmussen, H. Krauss and P. Avila. 1996. Marine flora of Rocas Alijos. In (R.W. Schmieder, ed.) Rocas Alijos. Scientific results from the Cordell Expeditons, Kluwer Academic Publishers, the Netherlands, pp. 227–235.

Watson, S. 1876. Botanical contributions. II. List of a collection of plants from Guadalupe Island, made by Dr. Edward Palmer, with his notes upon them. Proc. Am. Acad. Arts 11: 112–121.

Unauthenticated | 10.248.254.158Download Date | 8/20/14 5:02 PM