!42 



CETACEA 



the winter of 1883-S4. 1 The usual length of the adult ranges from 

 45 to 50 feet, the female being larger than the male. Whales of 



Fig. 79. — Humpbacked Whale (Megaptera boops). 



the genus Megaptera are found in the South Atlantic and in 

 both the North and the South Pacific. They 

 resemble those of British seas so closely that it 

 is doubtful whether the differences Avhich have 

 been observed, and upon which several species 

 have been founded, may not be individual peculi- 

 arities ; but zoologists have not yet had the 

 opportunity of examining and comparing such 

 a series of specimens of different ages and sexes 

 from different localities as would be necessary 

 to determine these points satisfactorily. 



Tympanic bones of Megaptera occur in the 

 English and Belgian Oags, although somewhat 

 less commonly than those of Balcma and Balcem- 

 optera ; they have been described under the 

 names of Megapteropsis and Burtinopsis. 



Balwnoptera. 2 — Head small and flat, and 



pointed in front. Body long and slender. Skin 



of throat plicated. A small falcate dorsal fin. 



Baleen short and coarse. Cervical vertebra? free. 



Scapula low and broad, with a large acromion 



and coracoid process. Pectoral limb tetradacty- 



H lous, small, narrow, and pointed. Tympanic 



I. (Fig. 81) long, much inflated, and rounded, with 



™ the involuted portion thickened and pyriform, 



& and the notch for the Eustachian canal sharply 



defined ; inner surface flattened, without the 



vertical groove found in Megaptera. 



The Rorquals, Fin-Whales, Fin-backs, Fin- 

 ners, or Razor-backs, as they are variously called, 



K) 



O 



o 



1 See J. Struthers, ' ' On the Anatomy of Megaptera 

 longimana," Journ. Anatomy and Physiology, 1887-89. 



2 Lacepede, "Table des Ordres," Hist. Nat. ties Cetacis, 

 p. xxxvi. (1804). 



