(Fig. 1) is a pouehless marsup ial with a semi prehensile short tail (ca. one-half the body length) that is well furred for the first 1-2 cm near the base and nearly hairle ss posterior to that (Emmons and Feer 1990). Face and dorsal pelage are a uniform grayish brown; cheeks and sides are paler gray with yellowish tinge ; feet are whitish ; and chin and ventrum are lighter and gray to buff in color with an orange tinge (Emmons and Feer 1990;Redford and Eisenberg 1992 ;Thomas 1888) .Captive adult females and males weigh 80--100 g and 90--150 g, respectively (Fadem and Rayve 1985) . Length of head and body of captive adults ranges from 170 to 200 mm and len gth of tail is 60--80 mm (Fadem and Rayve 1985). Compared with captive gray short-tailed opossum s, wild-caught adults are lighter (mean body mass, 71.4 g; range , 58-95 g; n = 11) and smaller (Redford and Eisenberg 1992); average (ranges in mm) measurements of wildcaught adults are total length, 212 .3 (178-270; n = 18); length of head and body, 143.2 (123-179; n = 18); length of tail, 69.1 (46-91; n = 18); length of hind foot, 17.7 (14-22; n = 18); and length of ear, 19.8 (14-25; n = 17).Measurements (in mm) from 1 preserved female (Thomas 1888) are length of head and body, 131; length of tail , 75; length of hind foot, 18; distance from muzzle to eye, 17.3; and length of ear, 15. Measurements (in mm) from 1 skull of an adult female M. domestica ( Fig. 2; Thomas 1888) are basal length, 35 .7; great est breadth of skull, 19.8; length of nasals, 17.8 ; greatest breadth of nasals , 4.6; least breadth of nasals, 2.3; intertemporal constriction (least breadth between orbitotemporal fossae), 6.0; palate length, 20.3; palat e breadth outside M3, 12.1 ; palat e breadth inside M3, 7.1; length of palatal vacuities, 2.9; combined lengths of basisphenoid and basioecipital bones, 12.6; length from basisphenoid-presphenoid suture to anterior tip of premaxilla, 23 .2; ratio of basifacial axis to basicranial axis, multiplied by 100, 184; and combined length of MI-3, 6.6 . Addit ional average skull measurements with range (in mm) of M. domestica (Wible 2003) are premaxillarycondylar length, 38 .7 (26.7-44.7; n = 27); greatest zygomatic breadth, 20.8 (14.3-25.0; n = 28); and length of mandibl e, 28 .8 (19 .0--34.4; n = 29).
