L893.] 



NATURAL SCIENCES OF l'l 1 1 1.AI iKI.l'l 1 1 A. 



407 



3. Perognathus femoralis J. A. Allen. 



Dr. Allen described this species in 1891. 4 Its cranial characters 

 never having been figured, I take this opportunity of illustrating 

 them from three specimens taken at the type locality during the past 

 year (1898). Femoralis differs from its allies fallax, californicus and 

 armatus in essential cranial peculiarities, as may be seen by a com- 

 parison of the figure with those of Mer- 

 riam. Its skull is most like that of califor- 

 nicus, from which it differs in the square- 

 cornered interparietal, the mastoid and 

 zygomatic breadths being equal and the 

 plane of occiput being on a line with the 

 postero- mastoid angles; the mastoids are 

 relatively larger in femoralis and the 

 coronoid process of mandible is longer 

 and sharply hooked. It may be further 

 remarked that the three California species 

 under consideration are a striking illus- 

 tration of the wonderful fertility of the 

 region they inhabit in the differentiation 

 of species, externally similar, but ana- 

 tomically distinct. P. femoralis probably 

 belongs to the penicillatus group of the 

 sub-genus Chostodipus, as defined by 



v^? 



>— — -~ — \_/^ 

 Fig. 3. 

 Mr. Merriani. 



Notes on fin' Affinities of Perognathus lordi, P. mollipUo&us and 

 Oricetodipus parvus. — In his admirable Revision of the North 

 American Pocket Mice Dr. Merriam enumerates three species whose 

 identity it was then impossible to determine, viz., the Aoromys lordi 

 of Gray, the Perognathus mollipilosus of Cones and the Gricetodipus 

 parvus of Peale. Dr. Merriam, in summing up his conclusions, refers 

 to these as follows: "My opinion is that this animal, ( P. mollipilo- 

 sus), will prove to be identical with P. lordi and both may be the 

 same as P. parvus of Peale." In another place (page 27) he states: 

 "all three come from the Pacific province, from Northern California 

 northward." 



Taking the above description of lordi as a basis, it remains to be 



• Bui. Am. Miis. X. II., Vol. 3, No. 2, 281. 



