REPORT ON THE CEPHALOPODA. 197 



the fact that the stained specimen has been largely denuded of its epidermis, which can 

 be seen in places adhering to the tentacle and also to the circumoral region. 



In addition to this, there was a small Cephalopod in the collection preserved in spirit, 

 which there can be no reasonable doubt is identical with the three specimens above 

 discussed although it was taken in the Atlantic. From the figure of it here given 

 (PI. XXXII. fig. 10) it is seen to have the same stalked eyes and long process carrying 

 the mouth and arms, the same form of body, and (so far as can be seen) of pen, and the 

 same distribution of chromatophores. Also since the figure just referred to was drawn 

 I have received another specimen from Dr. Pelseneer, who found it among the collection 

 of Pteropods on which he is engaged, and it is of special importance because it was taken 

 at the same locality as the three examples mounted by Suhm. It resembles the Atlantic 

 specimen so closely that the drawing might have been equally well made from either. 



The arms are rudimentary and carry each one sucker, and here it may be observed 

 that in every Cephalopod the arms pass through a stage in which they have each only 

 one sucker. In the case of Cranchia and allied genera, where even in the adult the 

 sessUe arms are very short, it is only reasonable to expect this one-suckered stage at a 

 much later period of development than in such forms as Loligo, where they reach a 

 comparatively greater length, and as above mentioned (p. 185), specimens of Cranchia 

 reinhardtii have been seen in the present collection, in which the arms were quite 

 rudimentary, although the animals had attained more than one-third of their usual 

 dimensions. In the present example the suckers stand upon small papillae, which are 

 obviously rudimentary arms, an arrangement not visible in the mounted specimens 

 (see fig. 10). 



Furthermore the correspondence between these small spirit specimens and the two 

 larger ones from the Southern Ocean, which must be regarded as the types of the species, 

 is so close that it is impossible to do otherwise than consider them as identical. The 

 resemblance is especially great in the form of the body, and of the fin and of the head, 

 though the neck and the ocular peduncles are not so long in the less as in the more 

 mature specimen. This last, however, is a phenomenon seen in the development of every 

 Cephalopod ; for example, in Sepia the eye is much more prominent in the embryo than 

 in the adult (compare KoUiker's drawing ^ with any of the illustrations in Pis. XVI. to 

 XXII.) and in the ease of Grenacher's pelagic larva ^ one of the stages observed (fig. 8) 

 has the eyes distinctly pedunculate, while in a somewhat later stage this appearance is 

 almost entirely lost (fig. 12). 



If the identifications above made be correct there is no doubt that the only character 

 by which the genus Procalistes can be diS"erentiated from Taonius disappears, and the 

 two genera must therefore be regarded as synonymous. 



Before leaving this subject, however, it is only right to mention that Professor 



1 Entwickel. d. Cephalop., taf. iii. figs. xxvii.-xxxi., Zurioh, 1844. ^ Zeitsehr. f. wiss. 'Zool, Bd. xxiv pi. xi- 



