12 PROFESSOE FLOWER ON RISSO'S DOLPHIK 



the former must have had near her at the time of her capture ; or, as small herds of 

 these Cetaceans generally travel in company, it might have been a member of the same 

 band. There is no evidence, however, in the present case of more than these two 

 individuals having been seen^ 



In general form the young animal closely resembles the old one ; but the head is more 

 rounded, the dorsal fin is not quite so high, and slightly more posterior in position, and 

 the pectoral fin is decidedly shorter in proportion to the general size of the body. 



These differences will be best appreciated by the following table of proportions, 

 the entire length of the animal being in each case taken as 100 : — 



Young. Adult. 



Length of pectoral fin 16-4 . 18-8 



Breadth of caudal fin 20-0 23-0 



Height of dorsal fin 10-3 12-7 



I think that the difference would be even greater, if in the entire length the caudal 

 portion of the body could be excluded ; for that this grows more in proportion than the 

 head and trunk, seems to be shown by the relatively more advanced position of the dorsal 

 fin in the adult. It is but natural to suppose that the locomotive appendages should 

 be more highly developed in the full-grown than the new-born animal ; and there is 

 certainly a similar alteration with age (at least as regards the pectoral fin) in the allied 

 genus Glohicephahis. 



I am indebted to Mr. Gerrard, jun., for the following dimensions, as well as for the 

 drawing of the animal (PI. I. fig. 4) : — 



ft. in. 

 Length, in straight line from the upper lip to notch in middle of 



caudal fin 6 1 



From the upper lip to anterior edge of dorsal fin (following curve) 2 11| 



From the upper lip to anterior angle of eye 9 



From posterior edge of dorsal fin to middle of tail 2 10 



From posterior edge of dorsal fin to angle of mouth 7| 



Length of eye-aperture 0^ 



Pectoral fin. — Length of anterior border 10 



Length of posterior border 7 



Height of dorsal fin 7J- 



Antero-posterior length of dorsal fin at base 10 



Width of caudal fin 1 2-i- 



Girth of body immediately in front of dorsal fin 3 8 



The upper parts and sides of the body were almost black, the lower parts nearly 



' It is stated by the late Mr. Jonathan Couch, in ' Land and Water,' March 19th, 1870, that an animal of 

 the same species was observed off the coast of Cornwall in the month of May 1869. 



