564 HARES FROM MEXICAN BORDER— MEARNS. voL.xvm. 



and (lecurved, those of western examples being shorter and straighter; 

 the nasals of eastern specimens are also the widest. The mandible is 

 higher and the wholp sknll heavier in Texan specimens than in those 

 from the southern border of New Mexico. In dentition this species 

 does not difter materially from the true L. texianus. 



Type. — No. |iff|? U.S.N.M. (Coll. International Boundary Commis- 

 sion). Adult female, from Fort Hancock, El Paso County, Texas. Col- 

 lected by Dr. Mearns, June 22, 1893. (Original number, 2353.) 



LEPUS TEXIANUS DESERTICOLA, new subspecies. 



^VE8TERN DESERT JACKRABBTr. 



Lepiis calif ornicm, Baird, U. S. and Mes. Bound. Survey, 1859, p. 47 (lower Col- 

 orado River of California. — Cooper, Am. Nat., Ill, 1869, p. 470 (Colorado 

 Valley). — Allen, Mon. N. Am. Rodeutia, 1877, p. 358 (in part; as to No. 

 1327, etc.). 



Geographic disirlhutUm. — This is a pallid race, from the desert region 

 between the Sonoyta Valley, of Arizona and Sonora, and the Coast 

 Range Mountains, of California and Lower California. On the Mexi- 

 can boundary line it occui^ies the whole of the Tule, Tinajas, Yuma, 

 and Colorado deserts. 



Description of type. — About the size of Lepns caUfornicus, with larger 

 ears. Above clay color, mixed with gray and black ; sides and gular 

 patch a little more ochraceous than in Lepus caUfornicus; under parts 

 tinged with ochraceous buff; ears scantily clothed, of the usual j)at- 

 tern, pale drab and white, with black at the apex posteriorly. This 

 specimen is in winter coat, but has molted on the front of the head, 

 where the new coat is seen to be no darker than the old. 



Description of young. — No. 60912, U. S. N.M. (Coll. International 

 Boundary Commission). A half grown female, taken with the type, 

 of which it was, perhaps, the progeny. It is still in the woolly coat 

 without much overhair. Color above drab gray; sides and gular patch 

 slightly more yellowish; rest of under parts yellowish white. 



Variations. — Sjiecimens from the deserts east of the Colorado Eiver 

 are larger, with relatively longer ears, and have the ui)j)er surface more 

 mottled. On the Mexican boundary, intergradation with L. t. eremicus 

 takes i)lace in the region between the Tule IMountains and the Sonoyta 

 River, In tracing it westward it is observed to gradually take on some 

 of the characters of Lepus caUfornicus. The pelage becomes shorter, 

 coarser, and plainer, losing the variegated or blotched appearance on 

 the back; the size is decreased; and the under parts are suffused with 

 yellowish brown. At the eastern base of the Coast Range Mountains the 

 two species meet, and possibly their ranges slightly overlap ; but, though 

 the phase of Lepus californicus found in the Coast Range Mountains 

 likewise shows some variations from the phase of the coast which 

 are in the direction of the characters of Lj. texianus, the two species 

 appear to be distinct. This fact warns us against the assumption that 



