72 MONOGRAPHS OF NORTfl AMERICAN RODBNTIA. 



leucopus, and this is particularly evident in those from the open, dryer parts 

 of Southern California, and especially such examples as No. 7185 from the 

 Colorado Desert region, where the coloration is a brisk fulvous, without dorsal 

 stripe. But nearly all the specimens can be matched by eastern examples; 

 and, moreover, all the northern ones are actually duiker than average leucopus, 

 while most of them show a distinct dorsal stripe. "The entire on/side of the. 

 fore leg below the .shoulder white!" In a part of the specimens this is so, and in 

 another part of the specimens it is not so; and the same is the case with ordi- 

 nary leucopus. It is evident, therefore, that the characters ascribed to the 

 supposed "gambeli" fall to the ground. 



Passing now to another Pacific-coast species, so-called, we will premise 

 that in establishing his H. "austerus", Professor Baird intimated his suspicion 

 that it might not prove valid. "It is barely possible," he says, "that my H. 

 austerus may be a northern variety of the common Califomian species" (/>. e., 

 "gambeli"), "of smaller size and darker color, somewhat like the gray and 

 smaller H. leucopus of Nova Scotia and probably Labrador, * * and further 

 materials will be necessary to decide the question." With the necessary addi- 

 tional material before us, we cannot only confirm the suggestion here made, 

 but we can also show a perfect intergradation between "gambeli" and "aus- 

 terus"; a melting of this last into "boylii"; and, finally, the positive identity 

 of "boylii" with "myoides", which last we have proved to be the same as 

 leucopus. 



The Simiahmoo specimens, which are, as we have just shown, referable 

 to "gambeli", are so much darker than "gambeli" from the dry, open parts 

 of California, that they stand rather nearer "austerus" in color than to 

 the former examples of the species they are supposed to belong to ! 

 Color thus giving us nothing tangible, we will interrogate dimensions, and see 

 if these show anything of specific value. We accordingly present a short 

 table ; most of our samples of supposed "austerus" being immature, and 

 therefore excluded as tending to vitiate the result. 



