34^ WHALES AND DOLPHINS 



cc. No grooving on throat. Dorsal fin when present at 

 or near middle of body. Notch in middle of 

 hinder margin of flukes. 

 e. Beak extremely long, narrow and forceps-like, 

 one-sixth to one-seventh body length. Teeth very 

 numerous in upper and lower jaws (Fresh-water 

 Dolphins), 

 f. Blowhole not crescentic in outline. 

 G. Blowhole slit-like, longitudinally placed. Beak 

 straight. Teeth 29 in each row. Dorsal 

 fin an indefinite triangular ridge. Body 

 colour lead black. Length about 8 feet. 

 Confined to Indian rivers 



Gangetic Dolphin (p. 338). 

 gg. Blowhole a rough oval, distinctly on left side 

 of head. Beak with distinct upward curve. 

 Teeth 33 to 36 in each row. Dorsal fin 

 triangular, moderate in height. Body colour 

 light grey and white. Length about 7 feet 

 6 inches. Confined to Yangtse-Kiang 



Chinese River Dolphin (p. 342). 

 ff. Blowhole crescentic in outline. 



H. Dorsal fin high, short based, triangular. Teeth 

 50 to 60 in each row. Length about 4 feet. 

 Inhabits estuary of River Plate 



La Plata Dolphin (p. 342). 

 hh. Dorsal fin very low. Teeth 26 to 32 in each 

 row. Length about 8 feet. Found in River 

 Amazon . . Amazonian Dolphin (p. 341). 

 ee. Snout either beakless. or beak when present never 

 more than one-tenth body length (Delphinid<e). 

 1. Dorsal fin absent or rudimentary, 

 j. Head without beak. 

 k. Teeth in upper and lower jaws. 



I. Teeth spade-shaped, 15 to 19 in each row. 



Body colour black. Length about 

 4 feet 6 inches 



Finless Black Porpoise (p. 312). 



II. Teeth not spade-shaped, 8 to 10 in each 



jaw. Body colour (in adult) white. 

 Length 12 to 14 feet 



White Whale (p. 286) 

 KK. Either without visible teeth or with a tusk- 

 like tooth several feet long projecting from 

 the front of the upper jaw. Body colour 

 mottled grey. Length 13 to 16 feet 



Narwhal (p. 284). 



