2. BUBALSiNA. 91 



3. Head long ; of adutt, about one-fourth the entire length. Baleen elongate, 

 broad at the base, with several series of rigid ceribral fhres, forming a 

 rigid fringe. Mnamel thin. 



2. EUBALiENA. 



Ribs 15 . 15 ; first like the others, single-headed. Tympanic bone 

 rhombic, nearly like that of Balaena. Head large ; of adult, about 

 one-fourth the entire length. Vertebrae 52. 



Eubalsena, Gray, Froc. Zool. Soc. 1864, 201 ; Ann. ^ Mag. N. H. 1864, 

 xiv. 348. 



Skull broad and depressed behind. The frontal bones broad, band- 

 like, transverse (see Cuvier, Oss. Foss. v. p. 375. t. 25. f. 1-4 of young, 

 and f. 5-8 of adult animal). Tympanic bone rhombic, large ; aper- 

 ture oblong, only sKghtly contracted at the upper end, about two- 

 thirds the length of the bone. Baleen thick, rather brittle ; enamel 

 thin ; internal fibres numerous, thick, in several layers, rather inter- 

 twined, forming a thick rigid fringe. Cervical vertebrae aU united 

 by the neural apophyses into a single crest (Cuv. op. eit. t. 26. f. 13). 



Fig. 6. 



Eubalsena Oapensis, jun. Cuv. Oss, Foss. v. t. 25. f. 2. 



Ribs 15 . 15, aU simple-headed, the last four pairs not reaching 

 the vertebrae. Sternum oblong (Cuv. t. 26. f. 11). Blade-bone flat, 

 rather broader on the upper edge than high, with a prominent acro- 

 mion (Cuv. t. 26. f. 7). Arm-bones short ; forearm-bones very short, 

 scarcely longer than the humerus. Fingers 5, short, the middle 

 longest, the second, first, and fifth successively shorter (Cuv. t. 26. 

 f. 23). Os hyoides (see Cuv. t. 26. f. 14). 



Cuvier observes that the skulls of B. Mysticetus and B, austrdlis 

 differ more from one another than the skulls of the species of Rorquals 

 (Oss. Foss. V. 375). 



1. Eubalsena australis. The Oajoe Whale. 



Uniform black. Skull convex. The nose of the skull high, 

 straight, and rather suddenly bent down in front ; the nose and the 



