1895. TROCEEDINGS OF THE J^ATIOXAL MUSEUM. 565 



L. melanotis and L. t. griseus of the Texan region are geographical races 

 of a common species, in the absence of jiositive proof of their Intergra- 

 dation. 



Dimensions. — Average measurements of 2 adult males: Total length, 

 560 mm 5 tail vertebr<\^, 110; ear from crown, 158; length of hind foot, 

 125. Average of 3 adult females : Total length, 571 mm ; tail vertebrte, 

 109; ear from crown, 171; ear from notch, 139; hind foot, 130. 



Cranial and dental characters. — The skull of this form, especially in 

 specimens from west of the Colorado Kiver, shows a decided approach 

 to the characters of Lepus californicus. Like that species, it is weak 

 and fragile, and armed with a light dental apparatus. It is extremely 

 low and narrow, with light supraorbitals, and short and narrow nasals. 

 The brain case is narrow, however, while that of L. californicus has 

 greater lateral expansion than usual. East of the Yuma Desert, the skull 

 of this subsi)ecies rapidly acquires the conformation of X. /. cremicus. 



Type. — No. If "-f ) Am. Mus. Nat. Hist. Adult female, from the western 

 edge of the Colorado Desert, at the base of the Coast Eange Moun- 

 tains, in San Diego County, California. Collected by Mr. Frank X. 

 Holzner, May 7, 1894. 



