191-1] Grinnell: Mammals and Birds of the Colorado Valley 253 



given of the type of Felis hippolestes aztecus (Merriam, 1901, p. 593). 

 Since the sagittal crest of our no. 10587 is very highly developed, 

 it may be an older animal. Merriam 's transverse diameter of bulla 

 in the type of browni is 16 mm., while in our smallest specimen it is 

 19; his upper carnassial length in browni is 20.5; in our least it is 

 21.5, which, however, belongs to the otherwise largest skull. The type 

 of browni came from the Colorado bottom, Arizona, twelve miles 

 below Yuma. 



There thus appears to be considerable variation, and it is probable 

 that there is really less to distinguish browni from aztecus than the 

 original description of the former indicates. However, our material 

 proves that there is a well-marked desert form of the cougar, char- 

 acterized, as compared with oregonensis, by smaller size, paler colora- 

 tion, and shorter pelage. 



CRANIAL MEASUREMENTS IN MILLIMETERS OF FELIS OSEGONENSIS BROWN I 

 FROM THE COLORADO VALLEY 



i Measured from plane of inferior surface of palatines vertically to highest point on dorsal 

 surface of frontals. 



Lynx eremicus eremicus Mearns 

 Desert Wildcat 

 Two bobcats were trapped by our party: a female (no. 10604) in 

 a patch of screwbean trees in the river bottom on the California side 

 five miles below Needles, February 21; and a male (no. 10605) in a 

 wash lined with palo verde and catclaw on the Arizona side north of 

 Mellen, February 27. In addition to these specimens, both saved as 

 skins and complete skeletons, there is in the Museum a skin with the 

 skull inside (no. 5620) taken by W. W. Holder at Mineral City 

 (=Ehrenberg), Arizona, in 1864. 



