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



I have examined the following specimens : — 



A skull from Cuba, presented by Mr. H. Christy to the British 

 Museum ; and a skeleton obtained at the same place, presented 

 by Mr. H. Christy to the Museum of the College of Surgeons. 



A skeleton from Surinam, in the British Museum. 



A skull from Jamaica, obtained from Mr. Gosse's collection. 



A skull from the West Indies. 



A skull in the British Museum, and two skulls in the College 

 of Surgeons, without any habitat, but which are most probably 

 from America. 



The skeleton of the young animal, from Jamaica, figured by 

 Sir E. Home, in the College of Surgeons. 



Five skeletons and two skulls from West Africa, from the 

 mouth of the Gaboon, purchased from M. Du Chaillu, and named 

 in his work M. Owenii. 



An imperfect skull of the Ajuh, obtained from the River 

 Kworra, by Dr. Vogel, presented by Dr. Baikie. Named M. 

 Vogelii. 



The genus is confined to nearly the same latitudes on the 

 American and African sides of the Atlantic — that is to say, be- 

 tween 10° south and 25° north of the equator. 



From the examination of the skulls and skeletons, I believe 

 that the Manatees living in Africa and America are specifically 

 distinct from one another. 



The most prominent characters that separate the species are 

 as follows : — 



1. M. senegalensis. 



The skull without any nasal bones; or the nasal bones, if 

 present in the flesh, are not contained in a pit in the sides of 

 the frontal and maxillary bones. The front edge of the frontal 

 rounded and thick, forming an arched hinder margin to the 

 nasal opening. The lower part of the gonys of the lower jaw 

 convex, rounded, prominent. The front upper incisive edge of 

 the lower jaw concave, with raised edges, with two small separate 

 conical tubercles fitting into a pit in the upper jaw. 



The species includes M. senegalensis, Desm., M. nasutus, 

 Wyman, M. Vogelii, Owen, M. Owenii, Du Chaillu. 



2. M. americanus. 



The skull with distinct, thick, subcylindrical nasal bones in- 

 serted in a notch on the side of the front edge, and a groove in 

 the upper margin of the frontal bone; front margin of the 

 frontal bone transverse, thin, ragged or toothed. The lower 

 part of the gonys of the lower jaw with a compressed bifid pro- 

 minence, which is often rugose. The front upper edge of the 



