4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 56 



Remarks. — The squirrels of the vS. variegatoides group are very 

 imperfectly known. The group includes several rather localized 

 forms which in color present a remarkably wide range of individ- 

 ual variation. Large series of typical examples are much needed 

 to make clear many doubtful points. The Panama form is doubt- 

 less most closely allied to dorsaiis of northern Costa Rica, but it 

 seems to differ from typical variegatoides mainly in the paler color 

 of the under parts in the phase with grizzled back. The three speci- 

 mens obtained, two adults and one about half-grown, all lack the 

 small upper premolar usually present in the squirrels of this group. 



Specimens examined. — Three, all from the type locality. 



MICROSCIURUS ALFARI VENUSTULUS, subsp. nov. 



Type from Gatun, Canal Zone, Panama. No. 17 1030, female 

 adult, U. S. National Museum (Biological Survey Collection), col- 

 lected by E. A. Goldman, March i, 191 1. Original number 20955. 



General characters. — Closely allied to alfari, but general color less 

 rufescent. Similar to brozvni, but darker above and below ; tail 

 edged with orange rufous instead of grayish white ; throat more 

 rusty brown. 



Color. — Upper parts, including outer sides of limbs, brownish 

 black, finely grizzled with cinnamon-rufous, or rusty reddish, the 

 general effect resulting from overlapping of black-tipped hairs with 

 rusty reddish subterminal bands ; head, and especially cheeks, clearer 

 cinnamon-rufous than back ; under parts, including inner sides of 

 limbs, grayish brown, somewhat irregularly suffused with cinnamon- 

 rufous ; ears brownish at tips, clothed on inner base with a partly 

 concealed patch of moderately long cream-buffy hairs ; feet dark 

 rusty brownish ; tail coarsely grizzled black and cinnamon-rufous, 

 rather broadly edged with the latter color. 



Skull. — Similar to that of alfari, but nasals narrower posteriorly 

 and jugal weaker than in the type of that species. 



Measurements.- — Type: Total length, 250 mm. ; tail vertebrae, 102 ; 

 hind foot, 40. Skull (type) : Greatest length, 37 ; condylobasal 

 lengtli, 32.8 ; zygomatic breadth, 23.2 ; nasals, 10.5 ; interorbital 

 breadth, 14; palatal length, 15; maxillary toothrow (small anterior 

 premolar absent), 5.5. 



Remarks. — The pigmy squirrels typified by alfari and usually 

 assigned to the subgenus Microsciurus constitute a group that seems 

 to merit full generic recognition under this name. Aside from the 

 subgeneric characters currently recognized the group is charac- 



