MARMOSA. 5 



Micoureus Less., Tabl. Regn. Anim., 1842, p. 186. 



Asagis and Notagogus Glog., Handb. Naturg., i, 1841, p. 82. 



Thylamys (sic) Gray, List Mamm. Brit. Mus., 1843, p. 101. 



Grymatomys Burm., Thiere Bras., i, 1854, p. 135. 



Cnica Liais, Climats, Geol., Faun, et Geog. Botanique, Bresil, 



1872, p. 427. 



Size small; pouch absent; fifth hind toe sometimes not longer 

 than the second; tail long; body slender; teeth large, strong. 



KEY TO THE SPECIES. 



A. Size small ; face without dark central streak. 



a. Under parts yellowish white. PAGE 



a/ Upper parts rufous M. murina 5 



b.' Upper parts cinnamon M. mexicana 6 



c.' Upper parts ashy brown; skull, 35 x 20. . .M. canescens 6 



d.' Upper parts brown; skull, 31 x 16.5 M. sinaloa 6 



e.' Upper parts gray M. cinerea 7 



b. Under parts buffy yellow or buff. 



a/ Upper parts drab brown M. insularis 7 



b.' Upper parts dark sepia brown M. oaxaca 8 



c.' Upper parts cinnamon or tawny ochraceous 



M. fulviventer 8 



2. murina (Didclphis!), Linn., Syst. Nat., i, 1758, p. 55. 

 MURINE OPOSSUM. Tlacnazin Raton in Guatemala. 



Type locality. Unknown. ("In Asia; America.") Brazil? 



Geogr. Distr. Central Mexico to Brazil. 



Genl. Char. Tail furry at base; ear large, rounded, naked, basal 

 projection long, pointed. Skull: nasals long, of nearly equal width 

 throughout their length; supraorbital ridges present, tips forming 

 postorbital processes ; temporal ridges not meeting in center of brain- 

 case. 



Color. General hue above deep rufous, sides paler; cheeks, throat, 

 chin, and lips buff; orbital ring and space between eyes and nose 

 black; under parts and inner side of limbs yellowish white or buffy; 

 outside of limbs like back; hands and feet flesh color; tail covered 

 with rufous hair at base, remainder pale brown. 



Measurements. Total length, 395; tail vertebras, 218; hind foot, 

 26; ear, 29. Skull: basal length, 33; length of nasals, 15; across 

 postorbital processes, 7.2; palatal length, 20; length of upper molar 

 series, 6.4. 



