SCIURIDJ3-SCIURUS TEPHROGASTER. 



'65 



I have met with no description published earlier than 1867 that seems 

 at all applicable to this species. So far as external characters arc concerned, 

 it might be regarded as a subspecies of S. cvstuans, the differences being far 

 less than between either of the subspecies of S. hudsonius, and rather less, or 

 certainly not greater, than obtain between S. cestuans cestuans and S. cvstu- 

 ans rufoniger. It was only the discovery of the presence of two upper pre- 

 molars (the first also large for a Sciurus) that led me to recognize it as 

 specifically distinct from S. cestuans. Five of the eight skins of S. tephro- 

 gaster contain the skulls, and in each are two upper premolars. On the other 

 hand, in examining the dentition of some twenty or more specimens of S. 

 cestuans, embracing about an equal number of each variety, I have met with 

 none having more than a single upper premolar. 



The habitat, of S. tephrogaster may be considered as embracing Southern 

 Mexico and Central America, and as extending southward over the northern 

 states of South America to Central New Granada, and probably to Ecuador. 



Tablk \SV I.— Measurements of seven specimens of Sciukus tephrogaster. 



Table LVII. — List of specimens examined of Sciurus tephrogaster. 



