no. 2073. HOLOTHURIANS FROM NORTHWEST PACIFIC— OHSHIMA. 267 



The characteristic spines borne by the scalelike plates measure at 

 most 1.02 mm. in length, commonly 0.5-0.7 mm., and 0.3 mm. in 

 diameter. As can be seen in those broken near the base, the spine is 

 composed of a bundle of several pillars, connected with each adjoining 

 one by slender crossbeams arranged in concentric circles. 



I take the genus to be characterized by the presence of 8 tentacles, 

 regardless of their shape and relative size. According to this defini- 

 tion the name Ypsilothuria is not synonymous with SpJixroihuria, 

 That genus, as represented by Y. talismani Perrier, seems to be refer- 

 able to the comprehensive genus Cucumaria, through such transi- 

 tional forms as EcMnocucumis typica Sars, Psolidium splisericum 

 Sluiter, etc. 



Habitat. — Pacific coast of tropical America, from Cape San Fran- 

 cisco and Galapagos Islands to Lower California (Ludwig, 1894; 

 Clark, 1913); Celebes, Moluccas, and Sunda Islands (Sluiter, 1901); 

 Laccadives, Ceylon, and Andaman Islands (Koehler, 1898; Koehler 

 and Vaney, 1905); Uraga Channel and Sagami Bay (Mitsukuri, 1897; 

 Augustin, 1908); off Koshiki Islands, west of Kyushu; Suruga Bay. 

 While in the tropical seas the bathymetrical range of this species is 

 very considerable, being from 131 fathoms (India) to 2,232 fathoms 

 (tropical America), in the temperate regions, such as Lower Cali- 

 fornia and Japan, the animal lives in depths not exceeding 400 

 fathoms. 



Genus COLOCHIRUS Trosehel. 



68. COLOCHIRUS INORNATUS v. Marenzeller. 



Colochirus inornatus v. Marenzeller, Neue Holothurien von Japan und China, 

 1881, pp. 130-132, pi. 5, figs. 7, la. — Theel, Challenger Holothurioidea, 

 pt. 2, 1886, pp. 77-78, 120, pi. 6,. fig. 8.— Mitsukuri, Actinopodous Holo- 

 thurioidea, 1912, pp. 221-224, pi. 8, fig. 73, text-fig. 40. 



Station 4875. One specimen. 



The specimen, measuring 19 mm. in length, 10 mm. in width, and 

 5 mm. in thickness, agrees well with the previous descriptions. The 

 flat cups lying in superficial layer of perisome are 40-76/z in diameter, 

 being much smaller than those described by v. Marenzeller and 

 Theel. 



Habitat — Japan (v. Marenzeller, 1881; ThSel, 1886); Mergui Archi- 

 pelago (Pearson, 1910); Tokyo Bay (Mitsukuri, 1912); north of 

 Kyushu. 



69. COLOCHIRUS DOLIOLUM (Pallas). 



Actinia doliolum Pallas, Miscellanea zoologica, 1766, p. 152, pi. 11, figs. 10-12. 

 Colochirus doliolum v. Marenzeller, Kritik adriatischer Holothurien, 1874, pp. 



303-304.— Mitsukuri, Actinopodous Holothurioidea, 1912, pp. 218-221, 



pi. 1, figs. 10-11. 

 Colochirus australis Ludwig, Beitrage zur Kenntniss der Holothurien, 1874, pp. 



12-13, pi. 6, figs. 15a-c. 



