no. 2073. HOLOTHURIANS FROM NORTHWEST PACIFIC— OHSHIMA. 287 



at the middle (pi. 11, fig. 35); length 370-665//, with a mean of 517 p.. 

 These are uniformly scattered in the general perisome as well as in the 

 walls of the tentacles and their digits. Calcareous ring consists of 10 

 segments, 1.2 mm. high. Polian vesicles 6, stone-canal single and 

 coiled in its course. Genital tubes once or twice branched near base. 

 Genital papilla situated in the middorsal interradius, close behind the 

 tentacular crown. Ciliated funnels few, scattered along the mid- 

 dorsal line and the left dorsal interradius. 



This genus has been represented by a single species, T. ferruginea 

 Verrill of the Atlantic, from which the present one differs by its much 

 greater size and the small number of tentacle digits. 



Habitat. — Suruga Bay. 



Type.— Cat. No. 34187, U.S.N.M. 



Genus MYRIOTROCHUS Steenstrup. 

 95. MYRIOTROCHUS RINKU Steenstrup. 



Myriotrochus rinkii Steenstrup, Videnskabelige Meddelelser fra den naturhisto- 

 riske Forening, 1851, pp. 55-60, pi. 3, figs. 7-10. — Theel, Note sur quelques 

 Holothuries, 1877, pp. 3-11, pi. 1, figs. 1-13. — Danielssen and Koren, Holo- 

 thurioidea, 1882, pp. 28-31, 79, 81, pi. 5, figs. 1-4; pi. 13, fig. 1.— Ludwiq, 

 Uber die Radchen der Synaptiden, 1892, pp. 358-360, pi. 16, figs. 12-14; 

 Arktische und subarktische Holothurien, 1900, pp. 166-167. — Norman, 

 Natural History of East Finmark, 1903, pp. 415-417, pi. 27, figs. 5-9.— Kali- 

 schewskij, Echinodermenfauna d. sibir. Eismeeres, 1907, pp. 9-11. — Clark, 

 The Apodous Holothurians, 1907, pp. 30-31, 128, pi. 8, figs. 21-22. 



Chirodota brevis Huxley, Journal of Penny's Voyage, 1852, pp. 221-222. 



Myriotrochus brevis Danielssen and Koren, Holothurioidea, 1882, pp. 31-35, 

 79-80, 81, pi. 5, figs. 5-7. 



Station 4798. Fifty-one specimens, of which 37 are complete. 



The largest individual measures 32 mm. in length and 8 mm. in 

 diameter. Diameter of wheels, 160-250/*; number of spokes, 15-21; 

 that of inward processes, 19-25. 



Habitat in the North Pacific. — Lorenz Bay and Plover Bay (Lud- 

 wig, 1886); near Pribilof Islands (Clark, 1907); west coast of Kam- 

 chatka. The limits of distribution recorded byLudwig (1900) have 

 recently been widened by Kalischewskij (1907) and Clark (1907), to 

 the east up to Bennett Island, longitude 147° 27' E., and to the south, 

 off the banks of Newfoundland, latitude 45° 35' N. 



96. MYRIOTROCHUS MITSUKURII, new species. 

 Plate 11, fig. 36. 



Station 4983. Two complete specimens and three fragments. 

 Station 4984. Two specimens. 

 Station 4985. One specimen. 

 Station 4988. One specimen. 

 Body cylindrical, 35 mm. long and 8 mm. across. Integument 

 soft and muscular, smooth to the touch, white and trauslucent. 



