]20 MR. OWEN'S DESCRIPTIONS OF 



processes are more developed than in the present specimen from Port Jackson. In Lo- 

 ligo coroUifera, Tiles, these labial processes have been compared by Bojanus to the in- 

 ternal shorter series of tubercles of a Medusa. But this structure illustrates only in a 

 very remote degree the relation of analogy subsisting between the Cephalopods and 

 Radiaries. 



The structure of the tongue, pharynx, and glandular appendages, presented nothing 

 remarkable. The cesophagus was slender, and continued of uniform breadth, as in the 

 Decapods generally, to the stomach, which presented the usual gizzard-like structure. 

 In the Octopods, as in the Nautilus, the cesophagus dilates into a crop'. 



The rectum in this Cephalopod was furnished with two lateral processes (fig. 16. 

 pi. XXL), of a flattened triangular form, and evidently adapted to constitute a valvular 

 apparatus for the protection of the anal aperture. They are attached at opposite sides 

 of this transversely extended orifice by their acute angles, from which a ridge is ex- 

 tended to the middle of the opposite base, so that when the valves are folded down upon 

 the vent (as in the figure above the number of reference,) the ridges fit into the aperture, 

 and accurately close it. In the Cuttle-fish (Sepia officinalis, Linn.) the corresponding 

 processes are of a rhomboidal form, with a thicker ridge on the side next the anal aper- 

 ture, which they are thus adapted to defend against any foreign substances which may 

 obtain entry into the pallial cavity. In Onychoteuthis and in Loligopsis the anal append- 

 ages are long and slender : in the latter genus Rathke" compares them to antennce ; and 

 since in these Cephalopods they cannot act the part of mechanical guards, it may be in- 

 ferred that they perform the function of instruments of sensation, and convey the sti- 

 mulus to contract, to the muscular sphincter which closes the outlet of the alimentary 

 canal. It is interesting to notice the relation of coexistence which these appendages 

 bear to the lateral fins ; for they are only present in those Cephalopods which have 

 the power of propelling themselves forward, and in which their use is therefore obvious, 

 as the orifices of the branchial cavity, in which the intestine terminates, are directed 

 forwards. In the Octopods the anus is not provided with these appendages. 



Of the remaining viscera of the Decapod in question I have only to notice the repro- 

 ductive organs : these were of the female sex, and exhibited the ova both in the ovary, 

 where they were inclosed in reticulate calyces, as in most Cephalopods, and in their 

 passage through the oviduct, where the ova show the true character of their external 

 surface, which is perfectly smooth and polished^ 



' It is evident from this difference of structure in the two groups of BibruncMata, that Aristotle took his ex- 

 cellent description of the digestive organs of the Malakia either from a Sepia or Teuthis : he says, " Mera Se to 

 UTOua evovcXLV oluofdyov fiUKpov trai (ttevov, tj^ojuevov 2e tovtov irpuKoliui' fieyav na'i Trept^ep?; opi'idwOrj." — Hist, de 

 Anim., lib. iv. c. 19. 



« M&moires de V Acad. Imp. de Petersburgh, torn. ii. (1833), p. 169. ' Ueber Perothis,' &c. 



3 I am not aware of any modern account of the mode in which the ova of the Cephalopoda are impregnated, 

 taken from actual observation. Aristotle, whose History of Animals is still the richest in details of the habits 



