S2 
JOURNAL OF MAMMALOGY 
In skull characters septentrionalis more nearly resembles isthmius 
vivatus, as these two forms, of all the Central American Microsciurus, 
alone have the post-palatal region extending beyond the plane of the 
last molar. This extension of the palate serves to separate septen- 
trionalis from all forms but isthmius vivatus, but from this latter it is 
separated by smaller molars. 
But two specimens of this squirrel were taken, both at Sabalos, 
cf and 9 . 
Dactylomys boliviensis sp. nov. 
Text figures 1 and 2 
Type, No. 38709, Dept, of Mammalogy, 9 , Mission San Antonio, Rio Chmore 
Prov. Cochabamba, Bolivia; altitude 1300 feet, August 18, 1915; collectors, Leo 
E. Miller and H. S. Boyle. The type is a well prepared skin with a perfect skull, 
fully mature and with molar crowns well worn. 
General characters. — Similar to D. dactylinus but somewhat smaller and colora- 
tion a uniform olivaceous gray. 
Color. — Upperparts, from between ears to base of tail, clothed with very long, 
lax hairs which are black at the base for three quarters of their length or more, 
and are tipped with buffy brown along the back and olive-buff on the sides, the 
general effect being difficult to describe but giving a distinctly olivaceous im- 
pression in most lights; crown with a patch of long clove brown hairs that form 
a sort of a hood extending as far as the ears; vibrissse very long and black; under- 
parts white to cream colored with narrow encroachments of the grizzled hair 
from the sides. Forelegs above, like rest of upperparts; below, like breast. 
Hind limbs, along inside and upper surface, cinnamon buff ; below like belly. Tail 
very long, practically naked and scaly except for space of about 60 mm. at the 
base, where the long hair of the back extends down onto the tail and is black in 
color, the tips of the hairs cream color. 
Detailed characters. — Toes, five^ in front, five behind. Ears small, sparsely 
haired, almost hidden in long hair of head. Eyes small, with a tuft of long vibris- 
sse arising just posterior to the eye. 
Skull. — Large and strongly built; nasals widening rapidly anteriorly, ter^ 
minating almost in same plane with premaxillse; superior outline of skull very 
flat; maxillary toothrows converging anteriorly almost to the midline; posterior 
portion of palate built out by a thin shelf -like extension of post palatal region; 
pterygoid processes very long, slender and meeting the auditory bullse; other 
skull characters and mandible normal for the genus. 
Measurements (taken in the field). — Total length, 710 mm.; tail vertebrae, 
410; hind foot, 60; greatest length of skull, 74.1; condylobasal length, 70.6; zygo- 
2 The fifth toe of the fore foot is so small that a lens is required to distinguish 
it with certainty. It consists mainly of a vestigial claw set in the plantar tubercle 
that formerly lay at the base of that toe. 
