321 



are few and widely separated ; there being no specimens from points 

 between Virginia and Southern Texas, and none between Texas and 

 Tehuantepec, Mexico, nor between these two last-named localities and 

 Fort Tejon, Cal. The small insular race known as "littoralis", from the 

 islands off the coast of Southern California, come in between* the Te- 

 huantepec specimens and the example from Merida. While there are 

 no very considerable breaks in the chain, the gradation would be more 

 complete if specimens could be included from other intermediate local- 

 ities. The specimens at hand are sufficient to show a very great but 

 still very gradual decrease in size southward, amounting to over 25 per 

 cent, of the mean size. The mean of the two extremes is 4.25, with a 

 difference of 1.04 ; while, with a single exception, there is a gap at no 

 point of more than 0.08. 



With this rapid decrease in size may be noticed a considerable range 

 of variation in breadth in specimens of nearly the same length, indicat- 

 ing the existence of an unusual amount of individual variation, the 

 ratio of width to length varying from 0.54 to 0.59. 



Measurements of fifteen skulls of UROCYON VIRGINIANUS. 



FELIS CONCOLOE. 



The amount of material available for the study of variation in size 

 with locality in the present species is too small to yield very satisfactory 

 results. In the eight specimens of which measurements are given below, 

 it will be noticed that there is a decided increase in size southward. 

 Between the three skulls from northern localities (one each from ISTor th- 

 em New York and Washington and Oregon Territories) and the three 

 (mature) skulls from southern localities (Louisiana and the Bio Grande, 

 Texas), the average difference is fully an inch, or about one-eighth of 

 the mean size. 



OF THE 



UNIVERSITY 



OF 



