138 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 97 
the few known adult specimens, sharply defined white. Fore and 
hind feet thinly haired, white to brown. Tail sparsely haired, the 
large scales plainly visible. Palatal notch extends anteriorly to a 
plane on level with middle of M’. Enamel pattern of molariform 
3-3-3-3 
teeth, 4-3-2323 
Comparisons.—Distinguished from western Amazonian representa- 
tives of P. guyannensis by consistently sharply defined white under- 
parts (more specimens may void this character), relatively longer 
tail, deeper incision of palatal notch, flatter, less inflated audital 
bullae, elongate, not squarely formed, hamular processes, and posterior 
ends of lips of incisive foramina converging toward midline. 
Remarks.—Within the range of hendeez a large number of forms of 
Proechimys have been described. Among them the following are 
subspecies of P. guyannensis (composite): semispinosus, brevicauda, 
gularis, pachita, rattinus, and hilda. The author took specimens of 
P. hendeei, probably assignable to P. h. nigrofulous Osgood, together 
with specimens of P. guyannensis gularis from the same trap lines on 
the banks of the Rio Napo, Ecuador. The type of nigrofulvus comes 
from the typical region of gularis, on the Rio Bobonaza. P. “‘hendeer’”’ 
elassops Osgood from southeastern Peru is a guyannensis with a super- 
ficial resemblance to hendeer. The description of P. rattinus from 
the Rio Ucayali, Peru, was based on the skull of an adult female 
(designated as the type) and the skin of an immature female. As 
already indicated, the type skull is referable to the species guyannensis. 
The skin, on the other hand, agrees closely with that of the type of 
P. hendeei and either represents that species or a parallelism akin to 
that noted in elassops. 
PROECHIMYS QUADRUPLICATUS, new species 
Holotype.—Adult female, Univ. Michigan Mus. Zool. No. 80080; 
collected October 21, 1936, by Philip Hershkovitz; original number 
M635. 
Type locality —Llunchi, an island in the Rio Napo, about 18 kilo- 
meters below the mouth of the Rio Coca, eastern Ecuador. 
Distribution.—Amazonian region of Ecuador and northern Peru. 
Characters.—Upperparts Ochraceous-Orange mixed with black, the 
median dorsal area entirely black, the black tipped spines overlaying 
the soft annulated hairs. Underparts sharply defined white; upper 
surface of fore and hind feet dark brown with a sparse covering of 
minute silvery hairs. Tail almost naked. Skullas in P. guyannensis; 
enamel pattern of molariform teeth, ——- 
Comparisons.—Distinguished from P. ignotus, the only other de- 
scribed form of the Quadruplicatus group, by richer coloration and by 
the well-defined median dorsal band. 
