288 



ELDREDGE 



known distribution of Diphsowa sirnilis (as separated from 

 Diplosoma uirens) includes Indonesia, the Great Barrier 

 Reef, Fiji, Japan, and questionably the Philippine Islands. 

 Didemnum grande, a widespread species, is found in 

 Japan, Philippine Islands, Malaysia, Australia, Tasmania, 

 south Arabia, and Palmyra in the Line Islands. Didemnum 

 quincunciale has been known previously only from Zanzi- 

 bar and Trididemnum c\i;chps from Australia and Madagas- 

 car. 



Tokioka (1967) studied the ascidians in the U. S. 

 National Museum and recorded four species from other 

 atolls in the Marshall Islands. These are: 



Diplosoma uirens Hartmeyer, 1909 (Leptoclinum 



uirens) — Ebon 

 Ascidia aperta Sluiter, 1904 — Rongelap 

 Pol\^carpa cr\^ptocarpa (Sluiter, 1885) — Bikini 

 Polijcarpa ittiayamae Tokioka, 1950 — Arno 



No specimens were found from Enewetak. 



Didemnids show an increase in diversity toward the 

 Indo-Malayan region. The didemnid fauna of Enewetak 

 contains a number of widespread species, showing its 

 strong faunistic affinity to the Indo-West Pacific. 



Seven species of larvaceans (Gcrber, 1981) and two 

 species of thaliaceans (salps) (Gilmartin, 1958) have been 



reported from plankton samples taken at Enewetak. These 

 species are discussed in Chapter 20 in this volume. 



CEPHALOCHORDATA 



Cephalochordata include the lancelets commonly 

 known as Amphioxus. A small cephalochordate sjiecimen 

 dredged from the lagoon at Bikini was identified provision- 

 ally as Notasymmetron caudatum (Willey) by Schuitz 

 (1953). At least one unidentified specimen was seen in the 

 Mid-Pacific Marine Laboratory collections. 



REFERENCES 



Eldredge, L. G., 1967, A Taxonomic Review of Indo-Paclfic 



Didemnid Ascidians and Descriptions of Twenty-Three Central 



Pacific Species, Micronesica, 2: 161-261. 

 Gerber, R. P., 1981, Species Composition and Abundance of 



Lagoon Zooplankton at Enlwetok Atoll, Marshall Islands, Atoll 



Res. Bull. 247: 1-22. 

 Gilmartin, M., 1958, Some Observations on the Lagoon Plankton 



of Eniwetok Atoll, Pac. &/., 12: 313-316. 

 Kott, P., 1980, Algal-Bearing Didemnid Ascidians in the Indo- 



West Pacific, Mem. Queensland Mus., 20: 1-47. 

 Schuitz, L. P., 1953, Fishes of the Marshall and Marianas Islands, 



Bull. U. S. Nat. Mus.. 202: 1-685. 

 Tokioka, T., 1967, Pacific Tunicata of the United States National 



Museum, Bull. U. S. Nat. Mus., 251: 1-247. 



