:-!l(i University of California Publications in Zoology [Vol. 12 



It is obvious that puertae is a local, arid Lower Sonoran race of 

 nigricans, the latter belonging to the closely-adjacent semi-humid 

 Upper Sonoran of the various coast ranges of San Diego County, 

 mostly on their western slopes. Typical puertae, as compared with 

 typical nigricans, shows, in addition to the characters given above, a 

 tail of uniform pale tawny color both above and below, instead of 

 dusky above at base. From T. cabezonai Merriam, possibly also a 

 subspecies of nigricans, pucrtat differs in more tawny coloration above 

 (this obtaining in small young as well as in adults), invasion of 

 tawny over under surface, more depressed rostral region of cranium, 

 narrower interorbital constriction and braincase, and more widely 

 spreading zygomata. From T. bottac palleseem Rhoads, pin rim 

 differs in smaller size, paler, more tawny coloration, lighter dentition, 

 weaker and more depressed rostrum and smaller auditory bullae. 



Transmitted September 24, 1914. 



