SQUIRRELS OF MEXICO AND CENTRAL AMERICA 83 



Measurements. — Average of five adults from type locality : total 

 length, 550.8; tail vertebrse 280.8; hind foot 66.2. 



Cranial characters. — Premolars \. Skull closely resembling that 

 of typical S. atireogaster but differing in slightly heavier rostrum, 

 larger and longer audital bullse, and in having the peg-like first premolar 

 set well inside the anterior angle of the second premolar. Five adult 

 skulls from the type locality average : basal length 51.2 ; palatal length 

 26.9; interorbital breadth 19.8; zygomatic breadth 33.9; length of 

 upper molar series 11. 3. 



General notes. — Sciurus goldmani h^diX^ a superficial resemblance 

 to 6". collicei nuchalis but may be readily distinguished by the black 

 bordered ears, with large white basal patches, and the uniform color 

 of thighs and back. The hairs on the back are coarser and stiffer. 



Specimens examined. — Ten : from Huehuetan, Chiapas ; and 

 Guatemala. 



HESPEROSCIURUS subgen. nov. (p1. I, fig. 5 ; p1. II, fig. 4). 



SCIURUS GRISEUS Ord. California Gray Squirrel. 



Sciurus griseus Ord., Journ. de Phys., lxxxvii, p. 152, 1818. 



Sciurus fossor V-EAI.Y., Mamm. and Birds U. S. Expl. Expedition, p. 55, 1848. 



Sciurus heermanni LeConte, Proc. Acad. Nat. Sci., Phila., p. 149, 1852 



(type locality California). 

 Sciurus fossor ant/ionyi yi^XKKS, Proc. U. S. Nat. Museum, xx, pp. 501-502, 



Jan. 19, 1898 (type from Campbell Ranch, Laguna, San Diego Co., 



California). 



Type locality. — The Dalles, Columbia River, Oregon. No type 

 specimen. Named from description. 



Distribution. — Pine and oak forests of Transition (and upper 

 border of Austral) zone from extreme southwestern Washington 

 through western Oregon and most of California (except coast belt 

 south of San Francisco) to northern Lower California, Mexico. 



Characters. — Size large ; tail long and bushy ; upperparts gray ; 

 underparts white. Pelage full and soft; under fur long and thick; 

 ears thinly haired. Teats : p. j- a. f i. \. 



Color. — Typical June specimens from Oregon: Upperparts, in- 

 cluding top of nose and base of tail, pale gray sometimes with slight 

 traces of yellowish on back ; outside of legs similar, but fore legs 

 sometimes a little paler; fore feet varying from dingy grayish white 

 to gray scarcely paler than back; hind feet gray, varying from a little 

 paler than back to grizzled blackish gray, occasionally with white 

 markings on hind feet and toes ; ears gray, sometimes suffused with 



