ATLANT. DEEP-SEA EXPED. 190 VOL. III.] 



ECHINODERMATA 



while 1 found only 8 in the 3 specimens whose tentacles 

 were intact. This difference cannot be of great signi- 

 ficance, however, for, judging from the material at hand, 

 the tentacles are apparently easily lost, but as easily 

 restored. It is therefore probable that my specimens also 

 originally had 10 tentacles. 



Peniagone wyvillii is new to the Atlantic region, as 

 it was previously collected only by the "Challenger" off 

 Christmas Island (stat. 271, 0° 33' S., 151° 34' W., 4438 m., 

 lemp. 1° Cel.). 



Peniagone ferruginea n. sp. 



(PI. 1, figs. 4—6.). 

 3 7.5. Stat. 48, 28° 54' N., 24° 14' W., 2800 to 3000 m. 



One specimen which measured: 

 Total length to the point of the dorsal 



processes 34 mm. 



Basal length to mouth 25 



Largest breadth of body 14 



Height of body 6 



Length of largest dorsal processes 10 



Breadth of dorsal processes 10 



Fig. 3. Calcareous deposits from Peniagone ferruginea n. sp. a — c from abactinal surface, d, e from actinal surface, / — h from the tentacles, 



i from the tube-feet. 



The body is oval and about twice as long and one 

 half as high as it is broad. The somewhat elongated 

 mouth is situated on the anterior ventral surface. The 

 anal opening is sub-dorsal, about 1.5 mm. above the 

 posterior extremity of the body. There are ten tentacles 

 with a disc diameter of 3 mm. and provided with 

 retractile processes. 5 ambulacral papillae are situated 

 on either side of the edge of the posterior half of the 

 body. The largest of these are 4.5 mm. long and 2.5 

 mm. broad. The hindmost papilla is situated at 2 mm. 

 from the anus. The space between the papillae is 1.5 

 to 3 mm. respectively. Besides these large ambulacral 

 papillae there are three very small papillae directly below 



the anus. On the dorsal surface, at the base of the 

 dorsal processes there are two small papillae on either 

 side, 1.5 mm. in length and 0.5 mm. in diameter. 



The body-wall is very thin and, together with the 

 ambulacral papillae and the tentacles, is abundantly fur- 

 nished with calcareous deposits. The dorsal deposits are 

 chiefly composed of spiny crosses with arms provided 

 with small processes (fig. 3 a). These processes may 

 frequently be as strongly developed as the branches which 

 give the deposits a rather irregular shape (figs. 3 b, c). 

 Simple, smooth, cruciform deposits and some peculiar 

 saddle-formed ones may likewise be found, but they are 

 rare. The deposits of the ventral surface are similar 



