12 METACHIRUS. 
11. *nudicaudatus (Didelplhys), E. Geoff, Cat. Mus., Paris, 1803, p. 42. 
RAT-TAILED Opossum. 
Type locality. Cayenne, French Guiana. (Allen.) 
Geogr. Distr. Costa Rica? to Brazil. 
Genl. Char. Size about equaling M. opossum but more slender; 
ears large, brown, rounded, naked. Skull: postorbital processes 
barely apparent; interorbital space broad. 
Color. Above grayish brown suffused on sides with yellowish, 
sometimes rufous; face rufous brown with a white or yellowish 
white spot over eye; under parts yellowish white; front of arms and 
outside of legs pale brown; indistinct yellow lateral line; tail furred 
at base, rest naked, scaly, brown grading to white at tip; hands and 
feet pale brown; ears slaty gray. 
Measurements. ‘Total length, 540; tail, 300; hind foot, 43; ear, 25. 
Skull: basal length, 61; greatest breadth, 36; length of nasals, 30; 
across postorbital processes, 11; palatal length, 36; length of upper 
molar series, 10.5. 
Fig. |1V. METACHIRUS FUSCOGRISEUS. ALLEN’S OPOSSUM. 
No. 8252 Am. Mus. Nat. Hist. Coll. Type. 
12. fuscogriseus (Vetachirus), Allen, Bull. Am. Mus. Nat. Hist., 
NCW: 19.00;, p. Tox. 
quica True, Proc. U.S. Nat. Mus., vi, 1885, ~.996 gee 
Temmuinck.) Alston, Biol. Centr. Amer., 1, 1832) 9meueeee 
(Part.) 
* Thomas, Cat. Marsupials, p. 333, gives this species from Costa Rica. 
