432 CETACEA. 



less pointed. I am disposed to believe that this male skull (No. 6, and Plate XXXIX, 

 fig. 1) is of the same species as the skull fig. 2 from the Hughli, which is only 2*25 

 inches shorter than the large skull from Chupra. By a comparison of the various 

 measurements of the skulls Nos. 1 and 6, it will be observed that the great differ- 

 ences lie between the relative proportions of the snouts, which are decidedly longer 

 in all of these female skulls than in the males. Of course, there is the other alter- 

 native that two or more species may exist, and that these males with small skulls 

 may be the males of a species of which the females are yet unknown, and that I 

 have never encountered the males of such large females as the specimen from Chupra. 

 The evidence before me, however, does not sanction such a conclusion, and until 

 further facts are adduced, there is no other course left but to regard the male as a 

 considerably smaller animal and having a shorter snout than the female, and that 

 individuals vary in size in different localities. 



Respecting the probable size attained by this Cetacean genus, it would appear 

 that the Chupra female had arrived at her limit of growth. In the largest female 

 from the Hughli in the accompanying tables the epiphyses of the vertebral processes 

 are firmly united with the vertebrge, and very many, but not all, of those of the 

 bodies are completely anchylosed to the latter, so that she is fully adult. Taking 

 the ascertained size in the flesh of this animal and the length of its skull as our 

 guides, it seems probable that the aged Chupra female must have attained a length of 

 nearly 9' 50 feet from the tip of its rostrum to the fork of its tail, whereas the length 

 of the largest male with quite as mature a skeleton and skull was scarcely 7 feet. 



Microscopic structure of the skin. — The skin structurally differs little, if at all, 

 from what obtains in the generality of the Whale tribe. The anomalous shape of the 

 snout and the condition of the parts around the spout-hole, however, led me to 

 examine the dermal constituents, and I here record my observations. 



The thickness of the skin, as in land animals, varies according to region and 

 other circumstances. Over the pectoral flippers, the skin is 5 millimetres thick, of 

 which the epidermic layer forms two-thirds of a millimetre, and is dark bluish-black 

 in section, the cutis being a clear white, of great consistence and sharply defined from 

 the underlying oily layer, which is 8 mm. thick and yellow in colour, and also 

 strongly fibrous. On a level with the dorsal fin, the ofl disappears out of this 

 layer, which becomes like the one overlying it, only somewhat yellow. Over the 

 vertebrae, in front of the dorsal fin, this fibrous layer is 1*50 inch in breadth from 

 side to side and 2*25 inches in vertical thickness. 



A piece of the cast-off, dried cuticle, when mounted in Canada-balsam and viewed 

 by transmitted light, to the naked eye and with a hand-lens, appears as a yellowish 

 or faintly brownish film, the darker tint marking fine parallel lines. Under a higher 

 power the linear arrangement is seen to be wavy (PL XXXVI, fig. 1), the minute 

 linear folds dove-tailing and running into one another, here and there. They, and 

 likewise the lighter coloured intervening spaces, indeed the whole tissue, are speckled 

 uniformly with minute dots, viz., scaly nucleated epithelial cells containing an 

 abundance of dark pigment. 



