a rare species of Octopus J'rom the Firth of Forth, 811 



sist6nt with our present knowledge of these animals. It must 

 be obvious, that the term octopodia, though very appropriate 

 for one of the sepise of Linnaeus and Pennant, cannot be applied 

 to a species of Octopus without a plain tautology, and because ' 

 the specific name, being then synonymous with the generic, 

 would be equally applicable to all the species. Until a more 

 determinate character, founded on structure, be discovered by a 

 careful dissection of the other species, I have called the present 

 species O. ventricosus^ from the rounded appearance of the 

 body in both the specimens I have seen, and in the figure of it 

 represented by Pennant. 



'Many excellent details of the structure and habits of the Se- 

 pia, the Loligo, and the Octopus vulgaris have been given by 

 Aristotle, Swammerdam, Monro secundus, Scarpa, Tilesius, 

 and Cuvier ; but, so far as I know, none of the species of octo- 

 pus, with a single row of suckers, have yet been opened by ana- 

 tomists. The O. ventricosus is the fifth species of cephalopo- 

 dous animals I have already procured from the Firth of Forth, 

 the other species being the Octopus vulgaris^ Loligo sagittafa, 

 Loligo vulgaris, and Loligo sepiola; and it is interesting to ob- 

 serve, that these species are nearly all the same as those met 

 with by Carus in the Mediterranean. That naturalist observed 

 in the Gulf of Genoa, specimens of the Oct. vulgaris, Oct. mos- 

 chatus, Loligo sagittata, L. sepiola, L. vulgaris, and Sepia offi- 

 cinalis. 



The following observations are chiefly taken from a recent a- 

 dult female specimen of the O. ventricosus, lately presented to 

 me by my friend Mr Coldstream, and to abridge the anatomi- 

 cal details, I have compared its organs with those of the O. vul- 

 garis, already fully described by Cuvier in his elaborate me- 

 moir on that animal, (Mem. sur les Moll. p. L) 



The body of the ventricosus is short, broad, slightly depressed^ 

 rounded, and a little dilated posteriorly, granulated and deeply 

 coloured with small reddish brown spots on the back, smooth and 

 light coloured on the fore-part. The upper margin of the mantle is 

 connected behind, across the whole breadth of the head, and has no 

 lateral expansions to assist in swimming. In the other genera Loligo 

 and Sepia, the mantle is free behind, and in these as well as in the 

 LdMgopsis, it is armed with lateral expansions to assist in swimming. 

 These expansions are supplied in the 0, ventricosus by the muscular 

 web connecting the base of the arms. The funnel is long, narrow, 



x2 



