260 Bulletin American Museum of Natural History. [Vol. XVI, 



brown; proximal third of naked portion of tail blackish brown, 

 apical two-thirds flesh-color or whitish. Facial markings reduced to 

 a very narrow eyering; head as light as in D. virginiana. 



Measurements. Four males measure: Total length, 874 mm. 

 (810955); head and body, 452 (385-500); tail, 446 (425465); hind 

 foot, 60.5 (55-66); ear, 60 (55-65). Three females measure: Total 

 length, 807 (740-850) ; head and body, 406 (350468) ; tail, 401 

 (382-430); hind foot, 57 (55-58); ear, 53 (52-53). Skull: Three 

 males, total length, 107 (101 no); basal length, 97 (91101); length 

 of nasals, 49 (47-50); zygomatic breadth, 63 (61-63.5); postorbital 

 breadth, 22.3 (2124); occipital breadth, 31.3 (30-32); breadth at 

 canines, 19.7 (19-20); upper toothrow, 34.3 (33-36). 



Specimens examined: 



Trinidad: Princestown, Caparo and Caura, 10 specimens. 



Island of Dominica: 3 specimens. 



Island of Grenada, 2 specimens. 



Island of St. Vincent, 2 specimens. 



Total, 17 specimens, n coll. Amer. Museum, 6 coll. Brit. Museum. 



A series of ten specimens from various near-by localities in 

 Trinidad (Princestown, Caura, and Caparo) are very uniform in 

 coloration and other characters, and are readily distinguish- 

 able from true marsupialis from Guiana by their much lighter 

 coloration and larger size. They vary chiefly among them- 

 selves in the color of the stiff overhair, which may be either 

 white or black, or variously mixed in the same individual. 

 St. Vincent, Grenada, and Dominica specimens are similar, 

 and were most likely derived from the Trinidad stock, having 

 doubtless been introduced into these islands from Trinidad. 



Didelphis marsupialis colombica Allen. 



Didelphis karkinophaga BANGS, Proc. N. Engl. Zool. Club, I, 89, Feb. 



23, 1900. Santa Marta region, Colombia. 

 Didelphis karkinophaga colombica ALLEN, Bull. Am. Mus. Nat. Hist. 



XIII, 1900, 193, Oct. 23, 1900 (Santa Marta, Colombia); ibid. 



XIV, 1901, 186 (measurements). 

 Type locality, Santa Marta, Colombia. 



Geographical Distribution. Eastern Colombia, south to Bogota, 

 and probably into northern Venezuela. 



Similar to true D. marsupialis but larger, with smaller ears, and 

 very much darker in coloration; head much darker with a tendency 

 to indistinct median and eye stripes, the latter more distinctly de- 

 veloped behind the eyes; whole upper surface of head with a general 

 blackish grizzled effect; ventral surface buffy, overlaid with a black- 



