364 I' ><ir< rsity of California Publications in Zoology [Vol. 10 



San Bernardino and San Jacinto Mountain region is reached. 

 From those points south through San Diego County, there is 

 a distinct increase. The matter of size, therefore, fails to argue 

 for a race dispar; hut it is usable as a fairly good average char- 

 acter for the distinguishing of a form in extreme southern Cali- 

 fornia. It is of further note, however, that even then, the wide 

 range in individual variation destroys the usefulness of this as 

 a specific criterion in a number of individual instances. For 

 example a male from San Mateo County (no. 3862) measures, 

 length 211 mm., tail 120, hind foot 27, this being coincident with 

 the largest of t lie specimens from Witch ( 'reek. San I >iego County 

 ( male no. 2983 . 



(4) Cranial features. As with general size of body there is 

 a slight increase in cranial mass in the series from extreme south- 

 ern California. But we are unable to discern proportional differ- 

 ences anywhere. The features mentioned by Osg 1 in this con- 

 nection are: size of mastoids, degree of arching of cranium, 

 mastoid width, interorbital width, width of nasals ami degree 

 of emargination of fronto-nasal sutures. In all these respects 

 there is much individual variation hut none thai is clearly cor 

 related wit h geographic areas. 



To summarize, there is not, from our material, warrant for 

 recognition of a race dispar as distinct from californicus. This 



possibility was anticipated by Osg I 1904, p. 128) in his 



remarks when describing ochrus, where he says: "P. c. dispar 

 is itself slightly paler than californicus, hut the principal reason 

 for recognizing it is its larger size and cranial characters. Should 

 these cranial characters prove inconstanl on the acquisition of 

 Larger series of true californicus, dispar would fall as a synonym 

 of nil i formats. 



As a further conclusion there now appears no justification for 

 considering femoralis as of mure than subspecific status, its 

 relationship to he hesl expressed in the trinomial, Perognathus 

 californicus femoralis. The main, if not the only, character of 

 this race as compared with californicus is its large size, particu- 

 larly of hind foot and ear. By our study, the range of the 

 formerly recognized <!i*i><tr becomes divided between that of 

 californicus and thai of femoralis, the range of the latter being 



