136 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 97 
resembles the eastern Andean races of Colombia than the coastal 
forms of Venezuela. 
Specimens examined.—Nineteen. The type, collection of the 
Chicago Natural History Museum; Rio Tarra, 18, collection of the 
United States National Museum. 
PROECHIMYS GUYANNENSIS CHRYSAEOLUS (Thomas) 
Echimys chrysaeolus Tuomas, Ann. Mag. Nat. Hist., ser. 7, vol. 1, p. 244, 1898. 
Type locality—Muzo, a town in the Minero Valley of the Rio 
Carare, western slope of the Cordillera Oriental, Department of 
Boyacé, Colombia. 
Distribution.—Western slopes of the Cordillera Oriental in the 
departments of Boyacd, the Santanders, and southern Magdalena, 
Colombia. 
Characters.—As in poliopus but with underparts sharply defined 
white, the hind feet whitish, slightly marked with brown. 
Remarks.—The type was “‘collected by a native.’ It is certain that 
it was not taken at an altitude of that of Muzo itself (1,240 meters) 
but must have come from somewhere farther down the valley. Four 
females and one male from Guamalito, near El Carmen, Norte de 
Santander, collected by the author, agree with the description of 
chrysaeolus. This race is distinguished from poliopus, and oconnella 
of Villavicencio, east of Bogota, by the absence of dark markings on 
the white underparts and by its paler hind feet. 
Specimens examined.—Five, from Guamalito, Norte de Santander, 
all in the collection of the United States National Museum. 
PROECHIMYS GUYANNENSIS MAGDALENAE, new subspecies 
Holotype.—Adult male, skin and skull, U.S. N. M. No. 280170; 
collected June 20, 1943, by Philip Hershkovitz; original No. 2098. 
Type locality—Rio San Pedro, a small stream in the northern 
foothills of the Cordillera Central, above the village of Norosf, alti- 
tude 178 meters, department of Bolivar, Colombia. 
Distribution.—Known only from the type locality and the lowlands 
west of the Rio Magdalena near Norosi. 
Characters.—Most nearly related to panamensis of Panama, and 
colombianus of the Chocé; distinguished from them by coarser mixture 
of black and ochraceous of back, fore and hind feet white with brown 
markings, not nearly uniformly brown; hamular processes narrower. 
Formula of enamel pattern Gaees 
Description of holotype-——Back Ochraceous-Orange mixed with 
black, sides of body Ochraceous-Buff, under surface sharply defined 
white; outer and inner sides of hind legs dark brown punctulated with 
ochraceous, hind feet white marked with brown; the brown line of 
outer sides of foreleg extending onto white forefoot; rostrum dark 
