60 TKOCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



the eyes being possibly indicated by the interruptions in the Lateral 

 margins ; the oval area on the left may be the remains of one of the 

 eyes ; ' whilst the posterior projection probably represents the remains 

 of a cartilaginous structure at the back of the head, and immediately 

 above the neck, such as occurs in the recent Squids ; consequently it 

 is most probably a dorsal aspect of the head that is presented, and if 

 this be so, it confirms the opinion expressed above, that the ligament 

 marked o was dorsal in position, and consequently attached to the 

 dorsal arms. Assuming, therefore, the order of the arms to be as stated 

 above, and that the ligaments i & j were attached, as they appear to 

 have been, to the arms d & e, these would be the two ventral or fourth 

 pair of arms, and consequently c & f the ventro-lateral or third pair, 

 b & (jf the dorso-lateral or second pair, and a & h the two dorsal arms 

 or first pair. 



If our reading of the order of the arms be correct, the tentacular 

 arms, if present, might be expected to be found between the arms 

 € & fon one side, and c & d on the other side. Now it will be seen 

 from Tig. 1 that between the arms e & f there is a rather wide space 

 and the surface of the slab is somewhat prominent, whilst between 

 the arms c & d the space, although not so wide, is very prominent 

 and bears a rather confused mass of booklets. Tentacular arms may 

 therefore have been present, but we have not been able to detect any 

 traces of them. 



There are no other remains of the body preserved, the edge of 

 the slab being only 5 mm. beyond the obtuse point at the back 

 of the head. 



As we have already stated, a buccal membrane is by no means 

 infrequent among the living Decapodous Dibranchiates, a membrane 

 somewhat similar to that here described being found among the 

 Onychoteuthidse, the members of which are provided with booklets 

 sometimes on all the arms, as in SJnoploteuthis, and sometimes only 

 on the tentacular arms, as in Ancistroteuthis. 



We think, then, that the presence of this buccal membrane in 

 A canthoteutMs confirms the Decapodous Dibranchiate character of this 

 genus. 



In conclusion, I desire to tender my sincere thanks to my colleague, 

 Mr. Edgar A. Smith, who has afforded me every facility in the 

 examination of the recent Cephalopoda imder his charge. 



' Or, as suggested in the discussion on this paper, of the buccal mass. 



