SOME NEW AND RARE CEPHALOPODA. 105 



founded the genus, render it a matter of difficulty and doubt to refer subsequently dis- 

 covered species satisfactorily to it. The desire expressed by M. de Ferussac, that addi- 

 tional observations should be made on the typical species, I shall therefore endeavour 

 to fulfil to the best of my ability, from the specimen which Mr. Bennett has transmitted 

 to me'. 



This specimen is smaller than the one described by Dr. Leach, but presents the same 

 enlarged, expanded, flaccid bag-like form of the mantle, terminated at one extremity by 

 a disproportionately minute pair of fins, and at the other by a head and arms of almost 

 equally diminutive size ; so that when the tentacles are retracted, as was the case in 

 Mr. Bennett's specimen, very little of the ordinary /acies of a Cephalopod is presented 

 to the observer. 



The dimensions of this specimen are as follows : 



Inches. Lines. 



From the posterior end of the body to the end of the tentacle out- 

 stretched 1 8 



root of the tentacle . . 11 



Length of the longest arm 3 



shortest ditto 14- 



fins 2 



Breadth of the two united fins 3 



Circumference of the thickest part of the body 3 



Breadth of the head 3J- 



The body or mantle is wrinkled and flaccid, in consequence of the very small space 

 occupied by the viscera ; and these are situated at its anterior part, and not at the bottom 

 of the sac, as in Loligopsis. It is probable that at the reproductive season the enlarged 

 ovarium may fill more or less of the pallial cavity ; but in the ordinary state of Cranchia 

 scabra the disproportion of the mantle to the contained parts is very remarkable, and 

 unique in the class Cephalopoda ; but a similar disproportion between the viscera and pal- 

 lium is found in some of the Pteropoda. 



The surface of the mantle in Cranchia scabra is uniformly beset with small round spots, 



' The following are the observations which M. Ferussac makes on the distinguishing characters of the genus 

 Cranchia : — " Pour fixer toutes les incertitudes a I'egard du genre Cranchie, et pour lui rapporter sans hesitation 

 I'espfece que nous faisons connaitre, il faudrait que celles qui ont ete decrites par le Dr. Leach fussent retiouvees 

 et mieux connues. Le caractere principal qui leur a ete assigne consiste dans la forme et position terminales 

 des nageoires. Sous ce rapport, ce genre se confond presque avec les Calmarets, mais ceux-ci en sont bien 

 distingues par la forme de leurs bras tentaculaires. II n'est separe des Calmurs que par la forme de ces memes 

 nageoires, qui sont reunies a leur extremite et semblent depasser ceUe du sac. Dans les esp^ces que nous y 

 rapportons et que nous avons pu observer, le port et I'ensemble des formes les distinguent bien plus encore des 

 Calmars ; mais nous ne pouvons faire la meme observation au sujet des especes signalees par le Docteur Leach, 

 parcequ'U a neglige de nous donner une description complete et detaillee, reproche qu'on peut faire quelquefois 

 a cet habile observateur sans porter atteinte ^ sa reputation bien acquise." — Ibid., p. 346. 



p2 



