144 Merriam New Mammals from Southern Mexico. 



fulvous, palest on inner sides of hind feet ; pectoral collar drab, 

 with tips of long hairs buffy ; chin, throat, middle of belly and 

 under side of tail, pure white with under fur plumbeous except 

 under tail, where the fur is white throughout; ears dull grayish 

 brown, bordered apically with a brown band, which is not very 

 well denned ; anterior edge fringed with whitish. 



Cranial Characters. Skull similar to that of L. arizonze, but 

 with audital bulla3 much smaller. 



Sciurus nelsoni sp. nov. 

 NELSON'S SQUIRREL. 



Type from HUITZILAC, MORELOS, MEXICO. No. 51157 9 ad. United 

 States National Museum, Department of Agriculture collection. Collected 

 January 1, 1893, by E. W. Nelson (original number, 4144). 



Measurements pf Type Specimen (taken in flesh). Total length, 500 ; tail 

 vertebrae, 246 ; hind foot, 68. Average measurements of 4 specimens from 

 type locality : Total length, 527 ; tail vertebrae, 262 ; hind foot, 70. 



General Characters. Premolars -f- ; size large, about equaling 

 S. cervicalis; color of upper parts uniform. No trace of nuchal 

 patch or rump patch. 



Color. Type Specimen : Upper parts from nose to tail grizzled 

 yellowish brown ; under parts grizzled fulvous, purest on throat 

 and breast, much mixed with black posteriorly; end of nose, 

 ears, and feet black, the feet (both fore and hind) more or less 

 grizzled (probably a seasonal character, as the feet are wholly 

 black in most of the specimens); tail black; upper side with 

 tips of hairs whitish ; under side bordered with whitish. Below 

 the broad subterminal black zone there is a concealed zone of 

 dull fulvous. 



Other Specimens. Some specimens are much darker than 

 others, and the difference seems to be seasonal. In some the 

 head, feet, and legs are intense black. The feet are almost 

 wholly black in nearly all the 14 specimens, and the under parts 

 are usually blacker than in the type. The tail is usually black, 

 washed above and on the sides with whitish, but in some speci- 

 mens the under side is grizzled from admixture of black and dull 

 buffy -gray. Two or three of the specimens show a whitish spot 

 (usually rather indistinct) at the posterior base of the ear. 



Specimens examined, 14 : 4 from Huitzilac, Morelos ; 9 from 

 Ajusco, Mexico, and 1 from Salazar, Mexico, 



