60 



specimen from Jamaica is figured by Sir Everard Home (Lectures, 

 iv. t. 54), and the head of this skeleton is copied under tbe name of 

 M. australis by Wagner (Saugeth. t. 381. f. 4), and the animal is 

 figured from a drawing by Mr. Gosse in the Figures of Animals 

 published by the Christian Knowledge Society, as the Manati. 



The more adult of the Museum skulls exactly agree with Dr. 

 Harlan's figures of the skull on which he founded M. latirostris 

 from the coast of East Florida. 



I am inclined to believe that all the skulls from America in the 

 British Museum, and that of a very young specimen in the same 

 Collection, belong to one species, though they vary considerably in 

 the height of the intermaxillary bones, in the comparative length 

 and breadth of the nasal opening, the extent of the bending down 

 of the front of the upper jaw, the completeness and incompleteness 

 of the orbit, and in the smoothness, roundness, or angularity and 

 rugosity of the gonyx of the lower jaw ; but I think that all these 

 differences may be referable to the age and sex of the specimens, the 

 upper jaw being more deflexed and lengthened as the animal in- 

 creases in age. All the older specimens have a small, conical, ru- 

 gose, bony prominence in the middle line of the front of the lower 

 jaw, and the apex of the coronoid process truncated and expanded 

 into an angle behind and before, as represented in De Blainville and 

 Cuvier's figures of M. australis and M. latirostris. This is even 

 the case in the skull of a very young animal with only the milk 

 teeth. 



On the other hand, in Dr. Baikie's skull of M. Vogelii, and in 

 M. De Blainville's figure of M. Senegalensis, the coronoid process 

 of the lower jaw is narrow above, with the hinder upper part ob- 

 liquely rounded off, and with a slight angle in front ; so that this is 

 probably the character of the African species. I may also remark, 

 that the front of the lower jaw of Dr. Baikie's specimen is produced 

 and very differently shaped from that of any of the American skulls, 

 and in this character it differs from M. De Blainville's figure of M. 

 Senegalensis ; but this difference may be only in consequence of its 

 youth. 



Dr. Harlan observes : — " Cuvier estimates the teeth at 36, nine 

 on each side ; in both my specimens they do not exceed 32, eight on 

 each side." 



In the very young skull above mentioned, which has holes for the 

 rudimentary upper cutting or canine teeth, there are only 24, viz. 

 six on each side ; and the two hinder on each side must have been 

 hidden in the gums. In the older skulls some have eight and others 

 nine on each side, but in most of them only six on each side are 

 perfect ; as the anterior one on each side drops out as tbe new ones 

 are formed behind, and in each of the skulls two hinder on each 

 side are in the process of development. 



But the question of the permanent specific difference between the 

 31. australis from Cayenne, the M. latirostris from East Florida, 

 Jamaica and Cuba, and between M. Senegalensis of Blainville (not 

 of Cuvier, which is like the first) and 31. Vogelii, must wait for 



