' Challenger ' Cephalopoda. 201 



beliiud, where it forms a flat, acute-angled plate, the posterior 

 extremitj of the shell ; it covers entirely, however, the dorsal 

 surface, which is slightly raised mesiallj and marked by a 

 number of faint striae radiating from the posterior end. The 

 ventral surface is much elevated on either side of a median 

 groove ; the last loculus occupies one sixth of the surface, is 

 bounded bj a wavj line, and deeply emarginate in the middle. 

 The inner cone is represented only by a narrow rib reaching 

 halfway along each posterior side of the shell and meeting its 

 fellow in a rounded angle beliind, from which a number of 

 radiating calcareous streaks pass outwards into the horny 

 termination. 



Hob. South of Papua (Station 188), 28 fathoms. One 

 specimen, $ . 



(Egopsidse. 



HiSTiOPSis, Hoyle. 



Histiopsis, Hoyle, 1885, Narr. Chall. Exp. vol. i. p. 273 {nomen tan~ 

 turn). 



Resembles CalUteuthis, Verrill, in the shape of the body 

 and fin and in the pigment spots scattered over it, but has a 

 web extending for some distance between the dorsal, dorso- 

 lateralj and lateral arms : the suckers are in two series. The 

 siphon has a suspensory ligament and a valve. The gladius 

 has not been removed. 



Histiopsis atlanticaj Hoyle {lac. cit.). 



The Body is short, conical ; acuminate and curving gently 

 downwards posteriorly. The fin is about one third the length 

 of the body and considerably broader than long ; each half 

 is roughly semicircular and narrows in to its insertion both in 

 front and behind. The mantle-margin is in general transverse, 

 but projects slightly as a blunt rounded angle in the dorsal 

 median line. The mantle-connective consists of a groove with 

 a narrow median fillet in the mid-dorsal line fitting into a 

 corresponding cartilaginous surface on the back of the neck, 

 and of a long linear ridge extending up to the margin, which 

 fits into a shorter groove on the base of the siphon ; this is 

 broad, short, and conical, and has a thick suspensory ligament, 

 through the skin of which two muscles may be distinguished, 

 and a distinct valve. 



The Head is as large as the body, rounded at the sides and 

 flattened above and below. The eyes appear to have been 

 enormous ; one is distended and protrudes from its orbit, whilst 



