KEY TO THE PRINCIPAL CETACEA 345 



gg. Size 42 feet to over 70 feet. No definite white 

 patch on outer side of flipper. 

 H. Size up to 49 feet. Whalebone for first 

 2 feet from tip of jaw generally white but 

 frequently with grey stripes, remainder 

 greyish black. Inner side of flipper 

 bluish-grey . . Bryde's Whale (p. 234). 



HH. Size 70 to 80 feet. Whalebone yellow and 

 slate coloured except in front on right side 

 where it is white. Inner side of flipper 

 white . . . Common Rorqual (p. 223). 

 ff. Whalebone plates black. 



1. Size up to 100 feet. Body colour blue-grey. 

 No large white area on under surface of 

 throat. Whalebone with coarse black 

 fringes. Throat grooves extending at least 

 to navel . . . . Blue Whale (p. 219). 

 11. Size up to 52 feet. White area of varying 

 extent on throat. Whalebone with fine soft 

 white fringes. Throat grooves ending some 

 distance in front of navel . Sei Whale (p. 227). 

 I. Whalebone absent. Teeth present though sometimes 

 concealed (Toothed Whales). 

 a. Tip of lower jaw ending an appreciable distance behind 

 foremost part of the head. Blowhole far forward on 

 head. 



b. Size 30 to 60 feet. Head massive, one-third body 



length. Teeth large, 18 to 28 pairs in number, 

 confined to lower jaw. Dorsal fin an ill-defined 

 lump. Flippers rounded . Sperm Whale (p. 257) 



rb. Size small, 9 to 13 feet. Head one-sixth body length. 

 Teeth 9 to 14 pairs, confined to lower jaw, slender 

 and curved. Dorsal fin well developed. Flippers 

 tapering . . . Pigmy Sperm Whale (p. 267). 

 aa. Lower jaw extending at least as far as tip of snout. 

 Blowhole some distance from tip of snout. 



c. Two conspicuous grooves forming a A-shape on the 



skin of outer surface of throat. Dorsal fin always 

 present, considerably behind middle of body. No 

 notch in middle of hinder margin of flukes (Bottle- 

 nosed or Beaked Whales), 

 d. Prominent forehead rising abruptly from, and 

 almost at right angles to, axis of beak 



Bottle-nosed Whales, 

 Hyperoodon, Berardias and Tasmacetns (pp. 270, 273, 282). 

 dd. Forehead not prominent, merging graduallv into 

 beak 

 Beaked Whales, Ziphius and Mesoplodon (pp. 275, 276) . 



