154 Transactions. — Zoology. 



the pit ; it terminates at the hinder margin of an irregularly 

 rounded vaginal aperture, the lateral margins of which are 

 folded in the usual way. 



The mammarv clefts are situated on either side of the 

 hinder region of the vulva, and about 1^ in. from it. Each 

 slit is about 1 in. in length, and is the opening of a pit 1 in. 

 deep, from the bottom of which a small rounded nipple rises 

 upwards. Above each mammary cleft, about 1 in. from it, is 

 a shallow furrow parallel with it, marking out with it a 

 slightly rounded area. 



The anus, which lies a short distance behind the vulva, is 

 2 ft. 5 in. from the middle cleft of caudal fin. 



The characteristic gular furrows extend from about 4 in. 

 from anterior end of jaw for a distance of 4 ft. 8 in., terminating 

 behind the level of the flipper. There are forty-five furrows 

 between the two flippers, while further forward the number is- 

 increased, and at the angle of the mouth eight additional 

 short furrows exist, on each side, dorsal of the longer ones. 

 Each ridge which separates two furrows is -|in. wide. 

 These ridges are not produced by mere folding of the skin, but 

 are delimited by straight grooves, -J- in. deep, into which the 

 epidermis, of course, dips. But in transverse section of the 

 skin it is evident that the blubber does not share in the 

 folding, for its inner surface is plane, and consequently it 

 is of less thickness below the furrows than below the ridges, 

 where it measures 1|- in. The middle series of furrows are 

 rather shorter than the more laterally placed ones, whose 

 length is given above ; the ventral rugae being 4 ft. 2-i- in., and 

 beginning Si- in. from chin. 



Measurements of External Features. 



Total leDgth from tip of snout to end of fluke, measured over 



back 

 Length of body — i.e., to notch iu fluke. . 



(in straight line) 

 Length of upper jaw, tip to angle of gapa 



lower jaw 

 Tip of snout to anterior base of pectoral limb 

 axilla 



base of dorsal fin 

 Length of base of dorsal fin . . 

 Height (greatest) of dorsal fin.. 

 Distance from posterior margin of dorsal fin to tip of body — i.e , 



median notch of fluke 

 Distance of vulva from anterior end 

 Greatest circumference of body, at a distance of 5 ft. 7 in. from 



snout 

 Circumference at axilla 



„ middle of dorsal fin (but, of course, excluding it) 



immediately anterior to root of fluke 



Weight, about 12cwt. (estimated). 



Ft. in. 



