THYSETERID^E. — CXCIII. 333 



a. Dorsal fin present, behind middle of back; teeth 18 to 30, very sharp; 

 head bluntish but not truncate; spiracles on top of head; length about 20 



feet Kogia, 578. 



aa. Dorsal fin wanting; teeth 40 to 50, large and blunt; head very long and 

 deep, truncate in front, the cavity ot the snout filled with oil and sper- 

 maceti; spiracles in front of head; length 60 to 80 feet. 



Physeter, 579. 

 578. KOGIA Gray. 



1102. K. breviceps (Blainville). Pigmy Sperm "Whale. 

 Warm seas, occasional on our coast. (Lat., short-beaded.) (£m.) 

 (A", grayi, goodei, etc.) 



579. PHYSETER Linnasus. (<pvcrr]TT]p, a whale, from (pvadco, 



to blow.) 



1103. P. macrocephalus L. Sperm Whale. Cachalot. 

 Blackish, paler below. Open sea, commonest far S. ; one of the 

 most valuable of the whales. L. ^80 feet; 9 much smaller. (Eu.) 

 (paxpos, long ; Kt(pa\f), head.) 



Family CXCIV. BAL^NID^E. (The True Whales.) 



Teeth disappearing before birth, their place taken in the upper 

 jaw bv an array of parallel plates with fringed edges, known as 

 baleen or whalebone. Eye very small, placed close to angle of 

 mouth. Spiracles separate, comparatively simple in structure ; 

 lower jaw very large and thick, its edge convex upward. Genera 

 8, species about 20 ; huge creatures, mostly of the colder seas. 

 feeding chiefly on small animals and sought by man for the sake of 

 the oil (blubber), and the whalebone. 



a. Bellv with conspicuous longitudinal furrows; pectorals shorter than head. 

 b. Dorsal fin well developed. 



c. Dorsal fin much nearer tail than head. 

 d. Whalebone slaty or pale; beak rather acuminate. Physai.us, 580. 

 dd. Whalebone black ; beak rather obtuse. . . Sibbaldius, 581. 



cc. Dorsal fin nearly median Bal.enoptera, 582. 



bb. Dorsal fin obsolete; back with a fleshy hump; belly with furrows; pec- 

 toral as long as head Megaptera, 583. 



aa. Belly without furrows; dorsal fin obsolete. 



e. Whalebone short and white (1 to 2 feet long). . . Agapiieixs, 584. 

 ee. Whalebone very long and blackish (7 to 12 feet long). Bal^na, 585. 



580. PHYSALTJS Gray, ((pio-akos, whale, from <pv<rda>, to blow.) 



1104. P. physalus (L.). Common Rorqual. Fixxer. Fin- 

 back. Razor-back. Black above, paler below. L. 70 feet. 

 X. Atl. (En.) (P. antiquorum Gray; Balcenoptera boops, and 

 musculus L.) 



