DESCRIPTION OF OPISTHOTEUTHIS DEPRKSSA ,X. SP. 395 



Apparently the same state of things in O. A(jass{cii, us put down 

 above, is described by Ven-ill in a different way. According to liim, 

 the depressed body is together with the head " closely united " or 

 " wholly adnate to the web connecting the arms, except at the post- 

 erior end behind the fins, where it is slightly free and overhangs a 

 little." Again, it is said that the head and body are so closely adnate 

 to the branchial membranes " as to entirely conceal the ventral por- 

 tions." The position of the siphon and branchial aperture is pointed 

 out by ^^errill as being remarkal)ly ''posterior." The terms used by 

 him are misleading in so far as they lead one to think that the body 

 had laid itself down in sudi a way as to have come int<j union with 

 the Avebs by its ventral surface, and tliat the siphon and the Ijranchial 

 aperture had shifted their p(jsitions along the ventral surface of the 

 body towards its posterior end. Such is, in our opinion, decidedly 

 not the case. The ventral portion of the body is nowhere to be 

 C(jnsidered as being C(jncealed, except perhaps the mantle-rim, which 

 is reflected inwards at the branchial aperture (a, fig. [)). On the 

 contrary, it stands, at least for the greater part, exposed more than 

 ever, only with this peculiarity, that it forms a part of the general 

 supericn- surface, thereby losing all definable boundaries from the real 

 dorsal region or from the outer surface of the umbrella. Xor is there 

 any ground for supposing that the siphon and the branchial aperture 

 have any way approached the original posterior end, Avhich is, strictly 

 speaking, to be sought somewhere near the middle of the upper surface 

 of the flattened body, behind the position of the dorsal cartilage. 

 While thus retaining their usual relative position to the posterior 

 body-end, they have shifted themselves a remarkable distance away 

 from the centre, and along the outer surface, of the umljrella. 



To go on with the description of our specimen oi' (f. deprcsm the 

 entire superior surface (fig. 2) is covered with a wrinkled and flabby 



