2 8o 

 I. Opisthopiis transver S71S Rathbun. 



1S93. Opisthopus transversus Rathbun. L. c, p. 252. 



1900. Opisthopus transvcrsus Holmes. Occ. Pap. Californ.^ Ac. Sc, v. 7, p. 97. 



1904. Opisthopus transversus Rathbun. Harriman Alaska Exp., v. 10, p. 188. 



1910. Opisthopus transversus Weymouth. Leiand Stanford Jr. Univ. Publ., n" 4, p. 61, textfig. 9. 



The species, which is not uncommon along the coast of California, inhabits a Holothurian 

 {Stichopus californicus) and a kind of boring limpet {Lucapina crenulata). According to 

 Weymouth, the only author, as far as I know, who gave an outline of the animal, though 

 not of its external maxillipeds, the suture between ischium and merus of these maxillipeds 

 varies considerably in distinctness in various individuals, and the abdomen of the Q "varies from 

 a width greater than that of the carapace to a size no greater than that of the male". 



Chasmocarcinops Alcock. 



1900. Chasmocarcinops Alcock. Journ. As. Soc. Bengal, v. 69, prt 2, p. 334. 

 This genus again contains but a single species. 



I. Chasmocarcinops gelasimoides Alcock. 



1900. Chasmocarcinops gelasimoides Alcock. L. c, p. 334. 



1903. Chasmocarcinops gelasimoides Alcock. 111. Zool. "Investigator", Crust., prt 10, pi. 62, 



f. 2—3. 

 1910. Chasmocarcinops gelasimoides Rathbun. K. Dansk. Vid. Selsk. Skr., 7. Raekke, Afd. 5, 



n" 4, p. 340, pi. I, f. 10, pi. 2, f. 12. 



■ Stat. 115. Kwandang Bay, north coast of Celebes. Depth 31 m. 2 9- 

 Stat. 213. Saleyer Island, south of Celebes. Depth up to 36 m. i cf juv. 



This species has been well described by Alcock and excellent figures have been given 

 already. Besides the "Siboga" specimens I had the opportimity of examining four adult specimens 

 (' cT, 3 9), collected by Prof. Sluiter many years ago in the Bay of Batavia, and belonging 

 to the Amsterdam Zoological Museum. 



The carapace is bat little broader than long, with the postero-lateral margins but very 

 faintly divergent backward, almost parallel. It is much curved downward in its anterior part, 

 but the front is visible from above, and its surface is provided with numerous granules, but 

 one patch on each hepatic region and one on each branchial area are destitute of such granules. 

 The regions are rather well defined and it are especially two longitudinal, somewhat pubescent 

 branchio-cardiac and gastro -hepatic grooves, which are conspicuous. 



Front small, bilobed ; its anterior margin, as seen in facial view, is concave^). Orbits 

 deep, distinctly seen in dorsal aspect, filled by the globular and granulate eye-peduncles, which 

 present on their ventral face, in the middle, a faint speek of pigment. Fronto-orbital distance 

 about one-fourth of the greatest width of the carapace. Antero-lateral margins sweeping backward 

 with an elegant curve, hairy, rather sharp, granulate, the granules being arranged in crowded 



i) Alcock figures it as consisling of two pvominent lobes. 



132 



