1906.] Allen, Mammals from Western Mexico. 



zygomatic breadth, 37.9 (37 . 5-38) ; interorbital breadth, 19 . 7 (18*. 5- 

 21); mastoid breadth, 30.4 (29-32) ; length of nasals, 36.3 (35-38). 

 There is very little sexual difference in size, either in the external 

 measurements or in the skull. 



The series consists almost wholly of old adults, the only young 

 specimens being three suckling young taken at Escuinapa the last 

 of December and the first week in January, and three others taken 

 as the same place Oct. 10. The series also represents both the 

 winter and summer pelages. The latter does not materially differ 

 from the former except in being rather more worn and somewhat 

 faded. 



This large Escuinapa series agrees perfectly with the type and 

 topotype of the species from the Plains of Colima. 



1 8. Lepus alleni palitans Bangs. 



Twenty-one specimens, n males, 7 females, and 3 without indi- 

 cation of sex, all adult, December 18-27; vicinity of Escuinapa and 

 Rosario. 



"Found singly and in pairs, in the low open grassy lands, and in 

 the open grassy foothills with patches of low bushes, to an 1 altitude 

 of 3500 feet. Most numerous on the foothills near the coast. The 

 young appear usually in June. This 'Jack' is probable the most 

 fleet of its genus. In running it will easily clear bushes four feet 

 high." J. H. B. 



This Jack-rabbit belongs to the Lepus alleni group but differs 

 so strongly from L. alleni that it probably will be found entitled to 

 specific separation. These winter specimens, compared with winter 

 specimens of L. alleni from southern Arizona, have the whole dorsal 

 region very much darker and stronger yellowish brown, the sides 

 are clearer, darker gray, the pelage much shorter, thinner, and less 

 woolly, the feet and ears much less heavily clothed, and the yellowish 

 white fringe bordering the ears much less developed. The limbs 

 hence look slenderer and longer. 



This species was described by Mr. Bangs (Proc. N. Eng. Zool. 

 Soc., I, 85, Feb. 23, 1900) from two specimens collected by Mr. P. 

 O. Simons at Aguacaliente, Sinaloa, a locality within the area in 

 which the present series was collected. Mr. Batty 's specimens are 

 therefore practically topotypes of palitans. As. Mr. Bangs's measure- 

 ments were from dried skins, and relate only to the ear and hind foot, 

 the following measurements, from fresh specimens, are of importance: 



Eleven males: Total length, 613 (507-637); head and body, 559 



