1 Challenger'' Cephalopoda. 231 



The Arms are equal and about half as long again as the 

 body ; they are short, stout, and taper gradually to blunt 

 points. The umbrella extends halfway up the arms, rather 

 more in the largest specimen. The suckers are round, 

 prominent, and deeply cupped, and there are about 30 on each 

 arm. The hectocotylus is not developed. 



The Surface is smooth, with the exception of three cirri 

 arranged in a triangle over each eye. Behind the left eye in 

 the largest specimen the skin is elevated into a number of 

 small papillae, and a few similar ones are seen on the back of 

 the medium-sized specimen. 



The Colour is a dull purplish grey above, inclining to pale 

 ochre below. 



Hob. South Atlantic, 600 fathoms (Station 320). Three 

 specimens, $ . 



Japetella *, n. gen. 



Ihe Body is gelatinous in consistency and semitransparent, 

 and more or less oblong in form. The mantle-opening is very 

 wide. 



The Arms are unequal, the longest (the third pair) being- 

 only about equal in length to the body. The umbrella 

 is small and the suckers arranged in a single row. 



Japetella prismatica, n. sp. 



The Body is of gelatinous consistency and semitransparent ; 

 it is somewhat longer than broad, flat on the dorsum, and with 

 the median ventral region raised into a prominent ridge, which 

 gives the body a prismatic form. The mantle-opening 

 appears to have been wide and to have terminated behind the 

 eyes ; but as it has been torn away from the head dorsally, it 

 is impossible to be certain of this. The siphon extends 

 almost to the margin of the umbrella, and is but slightly 

 conical, with a broad truncated extremity. There is no median 

 septum in the branchial cavity. 



The Head is about as broad as the body ; the eyes are 

 rounded and prominent laterally, the spherical lens protruding 

 from the middle of each. 



The Arms are unequal, the third being the longest, one 

 quarter longer than the body and about one third longer than 

 the fourth, which is slightly longer than the second, and this 

 than the first, so that the order of length is 3, 4, 2, 1. The 

 arms are stout and taper gradually to blunt points. The 



* Named in honour of Professor Japetus Steenstrup. 



