280 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 48. 



Genus PSOLUS Oken. 



84. PSOLUS SQUAMATUS (Koren). 



Cuvieria squamata Koren, Nyt Magazin for Naturvidenskaberne, vol. 4, 1844, 

 pp. 211-225, pis. 2, 3. 



Psolus squamatus Ludwig, Arktische und subarktische Holothurien, 1900, pp. 

 158-159. — Ostergren, Holothurioidea of Northern Norway, 1902, pp. 10-11. — 

 Vaney, Expedition antarctique Francaise, 1907, pp. 27-28. — Mitsukuri, 

 Actinopodous Holothurioidea, 1912, pp. 225-227, pi. 7, figs. 61-62, text-fig. 42. 



Psolus asper Augustin, Japanische Seewalzen, 1908, pp, 30-31, pi. 2, fig. 4, text- 

 fig. 20. 



Station 5017. One specimen. 



Station 5032. Seven specimens. 



Station 5033. One specimen. 

 According to Ostergren the specimens referred to this species by 

 Bell (1882), Pfeffer (1890), Sluiter (1895), and Bidenkap (1899) 

 belong to other species. According to Vaney, the name Ps. squama- 

 tus, var. segregatus, in Mitsukuri's list of synonyms should also be can- 

 celed. I think that Augustin's Ps. asper from Sagami Sea should 

 probably be referred to this widespread and rather variable species. 

 Habitat. — Various localities in the North Atlantic (see Ludwig, 

 1900); Pacific coast of Chile (Theel, 1886); California and Lower 

 California (Clark, 1901, 1913); Kuriles (Jaeger, 1833); Sagami Sea 

 (Augustin, 1908; Mitsukuri, 1912); east coast of Southern Sakhalin; 

 Nemuro Strait, Hokkaido. 



85. PSOLUS CHITONOLDES Clark. 



Psolus chitonoides Clark, Echinoderms from Puget Sound, 1901, pp. 335-337, pi. 3, 

 figs. 5, 6; pi. 4, figs. 6-10. 



Psolus californicus Fisher, Zool. Anz., vol. 29, No. 18,1905, pp. 573-576, text- 

 figs. 1-13. 



Station 4784. Three specimens. 



Station 4790. Two specimens. 

 The largest specimen is 60 mm. long, 47 mm. wide, and 26 mm. 

 thick. In the middle part of the odd ambulacrum a few scattered 

 pedicels are present, but only in large individuals. The character- 

 istic plates in the sole measure 100-3 10/* in diameter, with holes num- 

 bering above 20. End plate of pedicels is single in young individuals 

 but becomes multiple in older ones. Of the triangular scales around 

 the mouth the interradial 5 are larger, the inequality being more 

 emphasized in the young. There are about 7 scales between the 

 mouth and the anus, 20-22 in a transverse line where the body is 

 broadest. The specimens before me agree with those of Ps. califor- 

 nicus in almost every point, but differ by the presence of a complete 

 series of midventral pedicels in the latter. This again seems to be 

 referable to Ps. chitonoides, though the latter is rather briefly described 

 and shows some slight differences. 



Habitat. — Puget Sound (Clark, 1901); Monterey Bay, California 

 (Fisher, 1905); Aleutian Islands. 



