CALMA GLAUCOIDES 441 



of this inevitable colour resemblance of Calma to the spawn 

 on which it feeds, and in one English text-book the argument 

 for protective coloration is enhanced through careless quota- 

 tion of Hecht, the fish spawn being thereby represented as 

 laid o n stones and roots of Laminaria. As, however, the spawn 

 is laid under the stones and within the radical sacs, the 

 value of the colour resemblance seems very questionable, 

 especially if the cause of it be also considered. 



Internal Anatomy. 



Although Alder and Hancock (1) had referred to the simple 

 wide alimentary tract and the regular lateral repetition of the 

 gonads, the only considerable description of the internal 

 anatomy is that of Trinchese (9). Excluding certain errors 

 such as the identification of the renal pore as the anus, and 

 the saccular kidney as the great dorsal vein, Trinchese's account, 

 so far as it goes, applies well to the British species. His descrip- 

 tion of the radula and the contents of the gut added to that of 

 the external features places the generic identity of Forestia 

 and Calma beyond question. In fact there appears to be no 

 reason for giving the Mediterranean form separate specific 

 rank. It is curious that Trinchese did not recognize the 

 spheres which he saw in the semi-digested food as the lenses 

 of embryonic fishes. Hecht (6) gives a faithful description of 

 the kidney in its relation to the pericardium, but represents 

 the former as extending to the end of the body, whereas in 

 all the numerous specimens examined for this paper the kidney 

 lay entirely in front of the seventh ceratal group. Sir Charles 

 Eliot's revision of the genus (3 and 4) served to establish its 

 generic character, to collect together the scattered Calmas 

 of the literature and to exclude from among them Calma 

 cavolini of various authors which possesses none of the 

 special anatomical characters of a Calma. He emphasized the 

 peculiar nature of the radula, the great size of the stomach, 

 the absence of cnidosacs, and the mode of grouping of the 

 gonadial units as modifications correlated with the specialized 

 diet. To him the author's thanks are due for an introduction 



