560 BABES FROM MEXICAN BORDER— MEABNS. 



VOL. XVIII. 



Dimensions. — Total length, 570 mm; tail vertebra^, 75; eai^ from crown, 

 142; ear from notch, 118; length of hind foot, 123; length of head 

 (nose to occiput), 105. 



Cranial and denial characters. — The skull, though broad and high, is 

 much less massive than those of Lejrus caUotis and Lepus gaillardi. 

 The supraorbital processes of the frontal are less elevated and ex- 

 panded, and the postorbital process incloses a long and narrow, 

 instead of a broadly oval, foramen. The nasal bones are long, longi- 

 tudinally convex, and very broad. The rostrum and brain case are of 

 average dimensions. The dental armature is much weaker than in 

 L. callotis, and quite similar to that of L. gaillardi. 



Type. — No. 2317, Coll. International Boundary Commission. Adult 

 female, from Fort Clark, Kinney County, Texas. Collected April 0, 

 1893, by Dr. Edgar A. Mearns. 



General remarks. — This is the common "jackrabbit" of the Eio 

 Grande. It has been described by Audubon and Bachman, Baird, 

 Allen, and other writers, under the preoccupied names of L. callotis and 

 L. texianus, with which species it has been confounded. 



LEPUS GAILLARDI, new species, 

 GAILLARD'S JACKRABBIT. 



Similar to Lepus callotis, but smaller, paler, more yellowish, with rela- 

 tively shorter ears, and lacking the black nape patch. 



Geographic distribution. — Gaillard's jack rabbit was found only on the 

 east and west forks of the Playas Valley, bordering the San Luis Moun- 

 tains on the east side. 



Description of type. — Above pale ochraceous-cinnamon, mixed with 

 black; under side of tail white, its upper surface black, many of the 

 hairs being pointed with whitish; median black line of rumj) obsolete, 

 but indicated by a (mostly concealed) line of sooty, brownish, white- 

 tipped hairs; sides jmre white; rump and thighs white, lined with a 

 few black hairs, the former scarcely divided by a median dusky stripe ; 

 limbs white, stained with buff on their outer surfaces; gular patch buft", 

 becoming more ochraceous on front of shoulders and sides of neck; 

 head cream buflf, mixed with black, with a whitish area on the side 

 involving the eye; under parts white, with scarcely a trace of the col- 

 ored j)atches usually present in front of thighs ; ears scantily coated 

 with short hairs; their concave surfaces almost bare, with the usual 

 dusky spot along the posterior border; convex surfaces yellowish 

 brown, mixed with black anteriorly, white posteriorly and at apex; 

 long fringes of anterior edge of ear ochraceous buff, except subapically, 

 where, as in L. callotis, there is a tuft of black; fringes of tip and 

 posterior edge white; nape ochraceous butf. This specimen is in mixed 

 coat. Molting has commenced in front and proceeded backward from 

 the nose to the shoulders, and in the median line above to a point 

 behind the middle of the back; there are also scattered ijatches on 



