132 Dr. J. E. Gray on the Species of Manatees. 



firms this observation by the measurements of several skulls. 

 He does not believe that it affords a good specific difference. 

 In young specimens the nose is wider, because the facial part 

 of the skull is not so much protruded longitudinally (p. 406). 

 The nasal bones appear to vary in their position and relation to 

 the adjoining bones (p. 404). It is not impossible that the 

 position of the nasal bones may be used hereafter as a specific 

 character in the American Manatees ; and therefore he describes 

 the two extreme forms which he has observed among ten skulls 

 (p. 404). In one the nasal bone is' like those in the skull of the 

 M. senegalensis figured by De Blainville, and in another it is 

 like that in the skull figured by him as M. latirostris. 



The British Museum has, through the kindness of Dr. Kraus, 

 a skeleton from Surinam, from this series. 



As regards the African Manatees, Cuvier, in the ' Oss. Poss/ 

 V. 255, gives the following as the differences between the skulls 

 of the two species, and also the measurement of their parts : — 



"1. La tete d^Amerique est plus allongee a proportion de sa 

 largeur. 



"2. Get allongement appartient principalement au muscau 

 et aux narines. 



'^3. La fosse nasale est trois fois plus longue que large dans 

 le lamantin d^Amerique. Sa largeur fait les trois quarts de sa 

 longueur dans celui du Senegal. 



"4. Les orbites de ce dernier sont plus ecartees. 



"5. Les fosses temporales sont plus larges et plus courtes. 



" 6. Les apophyses zygomatiques des temporals sont beaucoup 

 plus renflees. 



" 7. En revanche elles ont moins de hauteur. 



'^8. La partie exterieure de la machoire inferieure est courbee; 

 dans Pespece d'Amerique elle est droite^' (p. 256). 



The front part of Guvier's figure of the skull is copied by 

 Dr. Harlan ; and the figures of the skull are copied by Schreber 

 (Saugeth. vii. t. 380. f. 1, 3, 4, and t. 381). 



In the 'Gompt. Rend. Acad. Scien. Paris,^ vol. ii. for 1836, 

 p. 363, and in the 'Institut,^ vol. iv. p. 114, M. Robert makes 

 some observations on the skeleton of the " Lamantin du Se- 

 negal." 



In the * Proceedings of the Boston Society of Natural History,' 

 vol. ii. for 1847, p. 198, Mr. Perkins gives an account of a Ma- 

 natus from the West Goast of Africa, named M. nasutus by Dr. J. 

 Wyman; and in the third volume of the same Journal for 1830, 

 at p. 192, Dr. J. Wyman describes the cranium of M. nasutus. 



M. de Blainville, in the ' Osteographie,' t. 3, figures the skull 

 of the Senegal Manatee, which appears to be the same as that 

 figured by Guvier, and the lower jaw (t. 1) and the vertebree (t. 5) 



