THE APODOUS HOLOTHURIANS 31 



220 ; the American material is thus seen to be very similar in this particular to 

 the Siberian. The Siberian specimens, however, averaged about 20 spokes to 

 the wheel, while those from Norway had about 16; so, in this particular, Ameri- 

 can specimens are more like the Norwegian. The average number of teeth, as 

 given by Ostergren, is 26.5-29.3, which is decidedly more than in the American 

 material. The number of spokes is about 57 per cent of the number of teeth 

 in Norwegian specimens, about 62 per cent in Newfoundland specimens, about 

 71 per cent in Bering Sea material, and about 76 per cent in high Arctic speci- 

 mens. It seems quite possible, judging from these figures, to draw the conclu- 

 sion that the number of spokes tends to decrease toward the southern limit of 

 the range of Myriotrochus rinkii. 



MOLPADIID^E. 



MOLPADIA AFFINIS (Danielssen and Koren). 



In the same bottle with the two specimens of arctica from the Kara Sea, 

 labeled "boreale" (see page 32), was a third specimen, 75 mm. long, with a few 

 scattered colored bodies and numerous calcareous tables exactly like those 

 figured by Danielssen and Koren ('82) for affinis; there are, however, no 

 anchors or rosettes. Although the status of affinis is not beyond question, this 

 specimen must for the present be referred to that species. 



MOLPADIA AMOEPHA, sp. nov. 

 (a/Liop^os, misshapen; in reference to the imperfectly formed calcareous tables.) 



PLATE XIII, FIGS. 14-22. 



Body rather stout, the caudal region short; skin thin, but not delicate. 

 Ground color, gray, more or less spotted, flecked or blotched with dark pur- 

 plish; in some specimens the purplish predominates, especially toward the 

 anterior end, which may become almost uniformly dark; the oral disc and tail 

 are, however, always gray. Tentacles 15 (in two specimens there were only 

 14), each with 3 terminal digits. Calcareous ring as usual. Deposits of two 

 kinds, elliptical phosphatic bodies, and calcareous tables ; elliptical bodies small 

 and dark purplish red, though some very small, yellowish-brown ones also oc- 

 cur; tables small and irregular, widely scattered in body-wall, but common 

 though not crowded, in the caudal region. They are very abortive, twisted and 

 incomplete, and it is upon this fact that I have based the name. 



3 specimens from "Albatross" Station 2779, lat. 56 6' S., long. 70 40' 30" W., 138 m. 



1 specimen " " " 2783, lat. 51 2' 30" S., long. 74 8' 30" W., 220 m. 



20 specimens " " " 2784, lat. 48 41' S., long. 74 24' W., 349 m. Types 



and co-types, Cat. No. 19,866, U. S. N. M. 

 24 " 3 stations. 



The largest specimen is 140 mm. long (10 mm. is "tail") and 45 mm. in 

 diameter ; the smallest is 52 mm. long and 20 mm. in diameter. The specimens 



