94 Fretp Museum or Naturat History — Zootoey, Vor. X. 
of female topotype: Greatest length 26.9; basilar length 24.5; zygo- 
matic breadth 14; nasals 11 x 3.2; interorbital constriction 5.6; palate 
13.9; front of canine to back of M 4 11.1. 
Remarks. This species appears.to have no very close’relative unless 
it be Peramys adustus of eastern Colombia which, although about the 
same size, is evidently much paler in color and lacks the extensive 
buffy pectoral area. Both the type and the one topotype obtained are 
imperfect, having been injured by ants while lying dead in the traps, 
the latter so badly that its mutilated body was preserved in alcohol. 
Marmosa madescens sp. nov. 
Type from Tambo Ventija, 10 miles east of Molinopampa, Peru. 
Altitude about gooo ft. No. 19689 Field Museum of Natural History. 
Adolescent male. Collected June 15, 1912, by W. H. Osgood and M. 
P. Anderson. 
Characters. A medium-sized species of very dark color and unbeaded 
skull, probably allied to M. incana and M. fuscata. Upper parts rich 
dark brown; back Prout’s brown shading to Vandyke brown on sides; 
frontal and interorbital region slightly paler brown; eye ring black, 
its anterior extension brownish; hairs of cheeks, chin, throat, breast, 
midventral and inguinal region self-colored creamy buff; hairs of sides 
of throat and belly and inner sides of arms and thighs creamy apically 
and broadly slaty basally; midventral area of self-colored hairs occupy- 
ing about one-fifth the transverse extent of the abdomen; tail thickly 
clothed with fine short hairs except the distinct scaly prehensory pad; 
upper side of tail dusky brownish except a short variable white tip; 
under side of tail irregularly whitish for distal two-thirds of its length, 
the remainder sooty; front of arms and legs brown; feet and toes whitish 
at least laterally. 
Skull rather elongate; supraorbital and temporal ridges only faintly 
indicated; nasals slender and slightly expanded posteriorly. 
Measurements. Type: Total length 259; head and body 120; 
tail 139; hind foot 19. Skull of type: Greatest length 32.2; basal 
length 30.9; zygomatic breadth 15.7; least interorbital breadth 6.5; 
nasals 14.7 x 3.5; palate length from gnathion 17.9; front of canine to 
back of M * 13.5; combined length of Ms '* 6. 
Remarks, Although comparison of actual specimens has not been 
possible, it is evident that this species has its nearest relationship with 
M. incana and M., fuscata, It differs from fuscata at least in the color 
of its underparts and doubtless other characters will be found upon 
comparison of specimens, 
