320 



Measurements of fifty-three skulls of VULPES ALOPEX et cars. 



UROCYON VIRGINIAN US. 



Measurements of a series of fifteen skulls of this species (all of the 

 available material) form a series grading by slight differences in length 

 from 3.73, the smallest, to 4.77, the largest. The largest specimens are 

 from Pennsylvania, Washington, and Virginia ; all -these exceed 4.60 in 

 length. The next in size are from Southern Texas and Southern Cali- 

 fornia, which range in length from 4.63 down to 4.50. Next come three 

 specimens from Tehuantepec, Southern Mexico, which range from 4.40 

 to 4.15. Between these and the next a series of three " littoralis ' 7 

 skulls from the islands off Southern California is an interval of three- 

 tenths of an inch, the three "littoralis" skulls ranging from 3.85 to 

 3.75. The smallest of all, however, is a single well-matured skull from 

 Merida, Yucatan, 3.73 in length, and hence smaller even than the small- 

 est "littoralis" skull, its breadth being only 1.98 against a breadth of 

 2.05 in the narrowest " littoralis" specimen. The localities represented 



