358 



MONOGRAPHS OF SOUTH AMU1UCAN KODENTIA. 



than two-thirds of the length of the car. The skull varies in length from 

 3.45 to 3.88; in breadth from 1.53 to 1.75. The lower jaw varies in length 

 from 2.17 to 2.77. 



The southern specimens are considerably smaller than the northern, as 

 shown by the measurements given in the subjoined table. Thus the average 

 length of five skulls from the vicinity of San Francisco is 3.80, width 1.72; 

 while the average length of nine skulls from Cape Saint Lucas, Lower Cali- 

 fornia is 3.52, width 1.58. 



This species differs from L caMotis, its nearest ally, in being consid- 

 erably smaller, in its darker and more rufous tints and relatively longer ears, 

 and in the small size of the lower jaw, which is relatively smaller than that 

 of any other North American species of Lepus. 



This species was first indicated in 1837 by Dr. Gray, who mentioned it 

 under the name L. californicus, without, however, publishing any description 

 of the species. Two years later it was described from the same specimen 

 by Dr. Bachman. Its only synonyms are Lepus rkhardsoni of Bach man 

 (1838), based on a specimen supposed to have come from California, and 

 Lepus bennetti of Gray. 



Geographical distribution. — The Lepus californicus ranges from the 

 northern parts of California southward along the coast to Cape Saint Lucas. 

 It seems to be mainly restricted to the region west of the Sierra Nevada 

 Mountains; but in latitude 35°, according to Dr. J. G Cooper, it extends 

 eastward, to the Colorado River. Further eastward, it is replaced by L. 

 callotis var. texianus. 



Tahle LII. — Measurements of LErus californicus. 



