6 MARMOSA, 
a.—mexicana (Marmosa), Merr., Proc. Biol. Soc. Wash., x1, 1897, . 
p. 44. 
Mexican MurRINE Opossum. 
Type locality. Juquila, State of Oaxaca, Mexico. 
Geogr. Distr. States of Oaxaca and Chiapas, Mexico. 
Genl. Char. Paler than M. murina, interparietal broader and 
shorter. 
Color. Above cinnamon rufous, graduating into ochraceous buff 
on belly; orbital ring black; end of nose to between eyes buffy; tail 
above brown, beneath paler. Some individuals have unicolor tails. 
Measurements. Total length, 330; tail vertebre, 186; hind foot, 20. 
3. canescens (Micoureus), Allen, Bull. Am. Mus. Nat. Hist., N. Y., 
1893, P- 235- 
ASsHY Opossum. 
Type locality. Santo Domingo de Guzman, Isthmus of Tehuan- 
tepec, Mexico. 
Geogr. Distr. Isthmus of Tehuantepec, northwesterly through 
States of Oaxaca, Guerrero and Michoacan to the Hacienda Magda- 
lena in State of Colima, Mexico. 
Genl. Char. Smaller than M. murina. Tail furred at base. 
Skull: nasals less expanded posteriorly than in M. murina, and the 
small posterior palatal vacuities absent. 
Color. Above ashy brown tinged with rufous, beneath white 
tinged with yellow; orbital ring black, reaching nearly to the nose; 
sides of face, neck, and between eyes yellowish gray; ears pale brown; 
tail pale brown spotted with flesh color, furred at base, rest naked, 
terminal portion often white; feet grayish white. 
Measurements. Total length, 266-288; tail vertebrae, 142-150; 
hind foot, 60-70; ear, 65. Skull: total length, 35.5; basal length, 
33.8; zygomatic breadth, 20.8; length of nasals, 16.3; anterior border 
of premaxille to posterior border of palatal floor, 18.8; length of 
mandible, 26; height at condyle, 7.6; at coronoid process, 11.7. 
4. sinaloz (Marmosa), Allen, Bull. Am. Mus. Nat. Hist., N. Y., 1898, 
|S RE 
SINALOA Opossum. 
Type locality. Tatemales, State of Sinaloa, Mexico. 
Geogr. Distr. State of Sinaloa, Mexico. 
Genl. Char. Similar to M. canescens in color, but smaller. 
Color. Above rufous brown, darkest on dorsal regions, paler on 
sides; beneath pale yellow washed with sooty; orbital ring black; ears 
and tail pale reddish brown; cheeks and throat pale yellow; feet and 
hands sparsely covered with yellowish hairs. 
