RORQUALS 157 



black above, white below. Dorsal fin high at com- 

 mencement of last third of body. Vent below hind 

 edcve of dorsal fin. Pectoral fin -*- of total length 



O o O 



of body. Plates of baleen about 325. Greatest length 

 200 mm. 



This is much the smallest of the Rorquals. It is 

 particularly to be distinguished from other Rorquals 

 by the white band which crosses the pectoral limb, 

 and by the sharp snout hence the specific name of 

 "rostrata." The "bone" too is always of a pale 

 colour, and there are but eleven ribs. Hence this 

 species of Bal&noptera is exceedingly easy to 

 characterise. 



This whale, which appears to have a liking for 

 the society of the larger Balcenoptera, pursues fishes ; 

 and Hunter noted the discovery of dog-fishes in the 

 stomach of an individual which he dissected. It has 

 been noted too that the stomach contains pebbles. 

 This is curious, for in other whales and in sea-lions 

 the same observation has been made ; possibly in 

 both cases the stones were taken up accidentally 

 while in pursuit of fish. One can hardly believe that 

 any idea of ballast entered into the mind of the 

 Cetacean. 



Balfenoptera musculus, Linnaeus* (known also as 

 B.physalus, Fabricius; B. rorqual, Lacepecle; Physalus 

 antiquorum, Gray), is in length 60-70 feet. Height 



* For anatomy see AlURlE, Proc. Zool. Sac., 1865, p. 206 ; HEDDLE, 

 ibid., 1856, p. 187 (called here Physalus duguidi, but probably the same 

 species really); and DELAGE, Arch, de Zool., 1885, p, i. 



