1902.] Allen, Opossums of the Genus Didelphis. 261 



ish grizzle produced by the longer black- tipped hairs; ears and feet 

 wholly brownish black; basal half of naked portion of tail black, the 

 rest yellowish white or flesh-color. 



Measurements. Five males, all from near Santa Mart a, Colombia, 

 measure: Total length, 822 mm. (710-980); head and body, 417 

 (355-456); tail, 405 (330-483) ; hind foot, 60 (57-68). Two females: 

 Total length, 768 (673-863); head and body, 377 (318-406); tail, 

 406 (355-457); hind foot, 56 (54-57). Skull: 4 males, total length, 

 98 (94-107); basal length, 90 (85-99); nasals, 15 (14.5-16); zygo- 

 matic breadth, 52 (48.5-57); postorbital breadth, 21; postorbital 

 constriction, u.i (10-12); occipital breadth, 29 (28-31); breadth at 

 canines, 19 (16-21); upper toothrow, 35 (34-36); molar series, 19.4 

 (19-20). 



Specimens examined: 



Colombia: Santa Marta and vicinity, 8 specimens, coll. Amer. 

 Museum. Also additional specimens in coll. H. H. Smith. Near 

 Bogota, 2 specimens, coll. British Museum. 



Total, 15 specimens. 



This form, based originally on a series of 8 specimens from 

 the immediate vicinity of Santa Marta, Colombia, is inter- 

 mediate in size between D. marsupialis and D. m. insularis, 

 being very much larger than the former and considerably 

 smaller than the latter, with much smaller ears. It is very 

 much darker in coloration than true marsupialis, which in 

 turn is very much darker than insularis, with which latter 

 comparison is unnecessary. As in the other forms of the 

 marsupialis group, the long stiff overhair may be either all 

 white, or the apical portion all black, or the two kinds of hair 

 may be combined in various degrees of abundance in the 

 same individuals. 



Didelphis marsupialis caucae Allen. 



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

 XIII, 1900, 192, Oct. 23, 1900 (Cali, Upper Cauca Valley, Co- 

 lombia); ibid. XIV, 1901, 1 86 (measurements). 



Type locality, Cali, Upper Cauca Valley, southwestern Colombia. 



Geographical distribution. Southwestern Colombia, east of the 

 Western Cordillera. 



Similar to D. m. colombica, but much darker throughout; a rather 

 distinct blackish eyering, and often a well-defined median black stripe 

 on the head, running from the nape forward, narrowing and terminat- 

 ing at a point on a line a little behind the eyes; rest of the head 



