Mr. Gray's Revision of the E qui dee. 241 



Explanation of Plate XI. 



Fig. 1. — Nyctiuomus Braziliensis — back view. 

 Fig. 2. — Its Head — front view. 

 Fig. 3. — Head, seen in profile. 

 Fig. 4. — Side view of the Cranium. 



Fig. 1, is reduced to two-thirds of the natural size. 

 Figures 2, 3, 4, are of the natural size. 



Art. XXXI. A Revision of the Family Equidae. By 

 Mr. John Edward Gray, M. G. S. 



Having occasion lately to examine most of the species of this fa- 

 mily, and being struck with the confusion that exists in the names 

 of the species, part of which was introduced by Mr. Burchell, in 

 his very interesting travels, I have been induced to send you a 

 revision of it. 



The older authors speak of the Horse, Mule, Onager, Ass and 

 Zebra, the last of which, they generally describe as having the 

 body (corpus) striped with black, brown, and white bands, three 

 inches broad, but take no notice of the colour of its legs : but 

 in Jonston's figure they are distinctly banded. They also de- 

 scribe, and Jonston figures several others, as the Ethiopian Horse, 

 t. 3. which has very large canine teeth, the mane the whole length 

 of the body, and the hoofs divided ; it appears to be a painter's 

 fancy. 2dly, The Indian Horse, which is banded like the Zebra, 

 but has the mane and tail of a Horse ; this is most probably only 

 an erroneous representation of the Zebra : and 3rdly, the Onager 

 with one horn ; t. 6. and the Onager with two horns, and divided 

 feet, the latter of which is most probably intended for the Two- 

 horned Rhinoceros drawn from memory, and the former appears to 

 be a fictitious animal altogether. Molina, in his History of China, 

 speaks of the Gncmcl or Jlucmal, the Equus bisukus of Grnel'm, 



