XII VOICE OF MESOPLODOM 369 



Ziphioid grooves upon tlie throat. Notlnng is known of the 

 structure of the internal viscera of this Whale. It appears not 

 to be really limited to the region of New Zealand, as is often 

 stated, for Malm has lately described a skull {Berardius vegae) 

 from Bering's Straits.-^ 



Ifesoplodon'^ is a world-wide genus embracing a number of 

 species ; on the lowest estimate seven species can be distinguished, 

 and Sir W. Flower would add two more. These are moderate- 

 sized Whales, 1 5 to 1 7 feet in length. In the skull the mesethmoid 

 is ossified ; the nasals are sunk between the upper ends of the 

 premaxillae. There are but a single pair of teeth in the mandible 

 attached to nearly the middle of its length (whence the generic 

 name). The vertebral formula is C 7, D 9 or 10, L 10 or 11, 

 Ca 19 or 20. The sternum consists of four or five pieces. The 

 amount to which the cervical vertebrae are fused varies ; but 

 some are always fused. 



The only species which has ever been stranded on the shores 

 of this country is M. bidens, an example of which was described 

 many years ago as the " Toothless Whale of Havre " ; it was an 

 old animal which had probably lost its teeth. E'evertheless it 

 received the separate generic and specific name of Aodon dalei. 

 The animal lived for two days out of the water, and made a sound 

 like the " lowing of a cow." An instance of the rarity of the 

 Whales of this genus is afforded by M. eurojiaeus, of which only a 

 single skull is known ; this was extracted from a dead body, found 

 floating, about the year 1840. It has never appeared since. 

 M. layardi is remarkable on account of the very large size of its 

 strap-shaped teeth ; these curve over the upper jaw in such a 

 way as to prevent 'the animal from fully opening its jaws. The 

 case is curiously paralleled by the Sabre-toothed Tiger. This 

 species is antarctic in range. From the opposite extremity of the 

 globe comes M. sUjnegeri, again known by but a single skull. It 

 is singular on account of the large size of the brain case, and is a 

 native of Bering's Straits. M. hectori has its two teeth situated 

 quite at the extremity of the mandible, and in this feature 

 approximates to the genus Berardius. It was, indeed, confounded 

 with that genus by one naturalist. 



^ Bilmng Svensk. Ahad. Handl. viii. 1883. 



^ Flower, Trans. Zool. Soc. a. 1878, p. 415 ; and H. 0. Forbes, Proc. Zool. Soo, 

 189.3, p. 216. 



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