1915.] Allen, Review of the South American Sciuride. 189 
In a few characters Microsciurus resembles Nannosciurus, but in other 
features the two genera are widely unlike, whatever may be the case with 
Scvurillus. The skull of the latter I have been unable to examine. (For 
comparative figures of the skulls and teeth of Nannosciurus and Micro- 
sciurus, see Plates VII and XIII.) 
The known distribution of the genus Microsciurus is the Andean region 
of South America, excluding the Bogota district, from the southern border | 
of Peru northward to Panama, and thence through Panama to central 
Costa Rica, from sea-level to about 8000 feet. Little is yet known of the 
limits of distribution of the species and subspecies, a number of which are at 
present known only from their type localities. 
Heretofore almost nothing has been recorded of the habits of these 
squirrels. The following notes by Mr. Leo E. Miller, who has collected a 
considerable number of these animals in western Colombia for the American 
Museum of Natural History, are therefore most welcome. He says: 
“T have always found the Microscvwrt much rarer than other squirrels, 
and usually in pairs. They seem to prefer the palm forests that are so 
abundant on the hillsides, where they feed on the various kinds of palm 
fruits and nuts. They invariably evince considerable curiosity, and can be 
approached to within a short distance before taking fright and hiding in the 
palm leaves. They move rapidly and gracefully, making long, daring leaps. 
In running over the leaves or branches they follow the lateral stems, and on | 
reaching the end, leap to another and repeat the same performance; other 
squirrels frequently ascend through the tree top or thick foliage by leaping 
crosswise from twig to twig, as if leaping from one ladder rung to another. 
But my experience with them is not extensive enough to enable me to say | 
that this is always the case.”’ 7 
Following is a revised list of the species and subspecies, as now recognized, 
with their type localities, and a statement of the number of specimens of each 
examined in the preparation of the present review. 
Microsciurus alfari alfari Allen. Volcano Turrialba, near Jiménez, Costa 
Rica. Specimens examined, 6, including the type. 
Microsciurus alfari venustulus Goldman. Gatun, Canal Zone, Panama. 
Specimens examined, 4, including the type and a topotype. 
Microsciurus alfari browni Bangs. Bogaba, Chiriqui, Panama; alti- 
tude 600 feet. Specimens examined, 3 topotypes. 
Microsciurus boquetensis Nelson. Boquete, Chiriqui, Panama; altitude 
6000 feet. Specimens examined, 2, type and topotype. 
Microsciurus similis similis Nelson. Cali, Western Andes, Colombia; 
altitude 6000 feet. Specimens examined, 12, including the type. 
Microsciurus similis fusculus Thomas. Juntas, Rio San Juan, Chocd 
