RORQUALS 169 



lateral foramina formed by the transverse processes, 

 which is so conspicuous a feature of those vertebrae 

 in Balanoptera and Megaptera. I counted 14 dorsal 

 vertebrae, 14 lumbar, and 21 caudals. 



The ribs are also fourteen, and the first two are 

 incompletely soldered together, not so completely 

 as in the " Hunterius temminckii" figured by Gray 

 in his Catalogue. The mode of fusion was different 

 on the two sides of the body ; but as this feature 

 is probably a mere variation, and not distinctive of 

 species or of genus, it is not worth while to give a 

 detailed description of the arrangement. 



The sternum is like that of a Rorqual ; it is cross- 

 shaped, but the arms of the cross are very short, and 

 the posterior termination is almost a fine point. The 

 pelvis consisted of but a single bone, but a rudi- 

 mentary femur may have disappeared. 



The one species is Rhachianectes glaucus, Cope ^ 



As is the case with so many whales, this species 

 varies somewhat in colour. It varies from a mottled 

 grey to black. The length of a full-grown example 

 is from 40 to 44 feet, but individuals somewhat 

 larger than this have been met with. Such indi- 

 viduals would yield some twenty barrels of oil, but 

 as many as seventy barrels have been obtained from 

 a larger specimen. The baleen reaches a length of 

 14 to 1 6 inches, and is light in colour, sometimes 

 nearly white. The Gray whale is limited so far 



* Proc. Acad. Nat Set., Philadelphia, 1868, p. 225. 



