244 M.Valenciennes on the Anatomy q/* Nautilus. 



whilst he designates the groups of tentacula placed about the 

 mouth as four appendices labiates tentaculiferce, Valenciennes 

 regards the flaps, from which proceed the tentacular tubes, as 

 arms. His two upper arms is Owen's hood. As this, accord- 

 ing to Owen, sends off two tentacula, he regards it as two 

 digitations of a similar kind as the remainder, united in the 

 middle. The flaps on each side, on which the seventeen tubes 

 with tentacula are situated, are called by Valenciennes the 

 second or outer arm ; the tentacula are considered by him as 

 analogous to the suckers of the Sepia, Owen calls the sin- 

 gle tentacular tubes arms, of which he reckons nineteen on 

 each side; Rumphius has twenty*. Valenciennes gets the third 

 (upper inward) and fourth (under inward) arm on each side 

 out of the front and hinder appendices labiates tentaculiferce 

 of Owen, each of which, according to him, has twelve ten- 

 tacula ; according to Valenciennes one has thirteen, the other 

 twelve ; according to Rumphius each has sixteen. Owen com- 

 pares the under appendices labiates to the pedunculated arms 

 of the Calmars, the upper ones as a further development of 

 the outer lip of the same. 



Valenciennes' view has much in its favour, inasmuch as the 

 genus of Cephalopods, Cirrotheuthis of Eschricht, has arms, 

 which are not furnished with suckers, but with delicate fili- 

 form tentacula. Valenciennes mentions two tentacula on each 

 of the upper arms, together therefore four ; Owen has only 

 two tentacula altogether upon his hood. Valenciennes has also 

 indicated the tentacula before and behind the eye. Their pre- 

 sence is an objection to his view; their structure, however, 

 differs from that of the other tentacula. 



The foliaceous organs, which Owen takes for the organ of 

 smell, are in Valenciennes' descriptions doubled ; for he has 

 an organ which Owen wants, in the vicinity of the eye, a tube 

 with a folded membrane in the interior, which he considers as 

 the organ of smell, because it is formed as in Fishes. Very pro- 

 bable. That the cephalic cartilage, which Owen has described, 

 is said to be wanting, seems to me somewhat suspicious. 



What has been communicated about the pericardium is 

 interesting, and differs from Owen's description in the num- 

 ber of the apertures t. And, lastly, what has been communi- 

 cated concerning the sipho is important, as is the confirma- 



* [Rumphius includes the two that are combined to form the hood, in 

 his series of twenty, which thus corresponds with Mr. Owen's enumeration. 

 —Ed.] 



■ f [Mr. Owen's words, in reference to the apertures here alluded to, are : 

 *• and on each side, at the roots of the branchiae, there is a small mammil- 

 lary eminence with a transverse slit, which conducts from the branchial 

 cavity to the pericardium." Loc. cit. p. 27. — Ed.] 



