12 PROFESSOR FLOWER ON RISSO’S DOLPHIN. 
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 fit. “2 eS ost _ 18:8 
Breadth of caudal fin . . . . . . 20:0 23°0 
Height of dorsal fin 2 27s." EOS 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 Globicephalus. 
I am indebted to Mr. Gerrard, jun., for the following dimensions, as well as for the 
drawing of the animal (Pl. I. fig. 4) :— ; 
ae Te 
Length, in straight line from the upper lip to notch in middle of 
caudal fin . 
From the upper lip to anterior riediie a dos fin (fallowing ccbtie) 
From the upper lip to anterior angle of eye 
From posterior edge of dorsal fin to middle of tail 
From posterior edge of dorsal fin to angle of mouth . 
Length of eye-aperture 
Pectoral fin.—Length of anterior fot ag 
Length of posterior border 
Height of dorsal fin : 
Antero-posterior length of dorsal fin at hee 
Width of caudal fin 
Girth of body immediately in front of dene fin 
wrFaoeqcodocdcdcdoeoncwn oS 
S 
| 
The upper parts and sides of the body were almost black, the lower parts nearly 
‘ Tt is stated by the late Mr. Jonathan Couch, in ‘ Land and Water,’ March 19th, 1870, that an animal of 
the same species was obseryed off the coast of Cornwall in the month of May 1869. 
