192 Fretp Museum or Naturat History — Zoétoey, Vor. X. 
stated by Waterhouse, has very large ears and a more uniform colora- 
tion than P. pictus and P. decoloratus. ‘The ear in the single topotype 
available measures approximately 25 mm. in length whereas in the 
largest of eight specimens of the species here described it measures 
only 18 mm., a difference of nearly forty per cent. Specimens from 
San Antonio and Crucero, Peru, are somewhat brighter in color than 
those from Tirapata, but are otherwise similar. 
Akodon zrosus baliolus subsp. nov. 
Type from Inca Mines, Inambari River, Peru. Adult male. 
No. 20108 Field Museum of Natural History. Collected Aug. 11, 1900, 
by H. H. Keays. 
Characters:— Similar to Akodon @rosus as represented by specimens 
from northeastern Peru (Moyobamba), but darker, more blackish, in 
color. General color above blackish bister or mummy brown, the rump 
rather more blackish than the anterior parts; lower parts correspond- 
ingly dark and showing less contrast than in @rosus. Skull averaging 
rather shorter with broader braincase and shorter nasals; otherwise 
similar to that of @rosus. 
Measurements:— Type: Total length 190; tail 83; hind foot (dry) 25. 
Skull of type: Greatest length 28; basilar length 22.7; zygomatic breadth 
14.7; breadth of braincase 13.4; nasals 9.8X 3.3; interorbital constric- 
tion 5.7; palatine foramina 5.9 2.2; upper toothrow 4.8. 
Remarks:— The slight characters distinguishing this form are con- 
stant in the small series examined and the great distance between its 
range and that of typical @rosus lends probability to the inference that 
larger series would be equally constant. In the thousand miles or more 
between southern Ecuador, the type locality of @rosus, and southern 
Peru, where the present form is found, there is much country not yet 
visited by naturalists and records of this species are few, but there can 
be little doubt that it has nearly or quite continuous range along the 
east base of the Andes from Ecuador to Bolivia. 
Dasyprocta nigriclunis sp. nov. 
Type from Sa6é Marcello, upper Rio Preto, Bahia, Brazil. No. 20746 
Field Museum of Natural History. Adolescent female. Collected 
March 23, 1914, by Robert H. Becker. Original No. 559. 
Characters:— A very distinct species with jet black nape and rump 
and hairy ferruginous ears; hairs of nape elongated to form a slight 
nuchal crest; size medium; general relationship probably with Dasy- 
