378 DISCOVERY REPORTS 



laminae, of which the most interior is reduced. I ought to point out here in connection 

 with the general problem of adaptation that, though the gills are reduced in size, the 

 laminae are much more folded, so that the surface of each filament is increased. The 

 median adductor is very small, as in C. umbellata (Ebersbach, I.e., fig. 3). On the 

 other hand, owing to an excessive increase of connective tissue, the pallial cavity has 

 become subdivided completely into two, a very unusual condition (cf. Robson, 1928, 

 p. 261). 



Alimentary eanal (Fig. 4). The mandibles are present and, though somewhat soft, are 

 normally developed. The palatal lamella of each is very small. The radula is absent. The 

 anterior salivary glands are very small. There are no posterior salivary glands. The 

 oesophagus is straight, and there is no crop. The lower end of the canal shows some 

 peculiar features, which must be more fully discussed elsewhere. The stomach is 

 equipped with a remarkably well-developed grinding apparatus. It contained a few 

 fragments of Polychaeta. The caecum is much larger than the stomach, and may include 

 part of the "third stomach" seen in Opisthoteuthis and C. umbellata. Its contents were 

 so finely reduced that it was impossible to identify them. The intestine is bent on itself, 

 as in Opisthoteuthis. 



Reproductive organs {S) (Fig. 5). There is no external trace of sexual differentiation, 

 e.g. no abruptly enlarged suckers as in S. albatrossi and Opisthoteuthis (Sasaki, 1929, pp. 8, 

 11). The internal organs are like those of C. umbellata (Ebersbach, loc. cit., Text-fig. 17) 

 in general, but the proportions of the first accessory gland to the (conjoined) second and 

 third is different. 



Remarks. This interesting form is like no described species. It seems to be most 

 closely related to C. megaptera in external appearance. The internal organs are not un- 

 like those of C. umbellata. The external appearance differentiates it at once from the other 

 Antarctic species of Cirromorpha {S. mawsoni. Berry). It is a pity that Hoyle's Weddel 

 Sea form (191 2) was only fragmentary. 



I hope shortly to publish a general discussion on this group. In the meantime, I must 

 point out that the question of the adaptive significance of many of the peculiar features 

 of these animals is rendered far more open than my recent account (1926) would lead 

 one to suppose. In spite of the presence of some gelatinous tissue in C. glacialis, the 

 arm- and fin-musculature is singularly powerful. The suckers are, if simpler in structure, 

 more muscular than those of many Octopodinae, and are strangely assorted with the 

 feeble mandibles and the absence of the radula. The gills, if small, have their small size 

 compensated by the increased surface. The funnel and locking-apparatus are powerful; 

 the adductor pallii medianus, as in C. umbellata, is feeble. This sketch will sufficiently 

 indicate that we have to deal with an actively swimming and darting form with need for 

 an ample supply of oxygen. Its diet seems to be that of a carnivore, but it is not easy to 

 reconcile the lack of radula and the weakness of the jaws with the presence of powerful 

 suckers, unless it be that it is a carrion eater and the suckers are used not for grasping 

 prey, but in coition. 



