1902.] Allen, Opossums of the Genus Didelphis. 263 



eyering, continued both in front and behind the eyes as an ill- defined 

 blackish spot; ears and feet black, as usual in the group; naked 

 part of the tail black for the basal third, the rest yellowish white. 

 Coloration in general as in all of the darker forms of the marsupialis 

 group. 



Measurements. Four adult males from Eten measure as follows: 

 Total length, 829 (730-930); head and body, 425 (390-480); tail, 



399 (33 -4S ); mnd foot > 6l (5 6 ~ 6 7)' ear 5 6 (5 2 ~ 60 )- A female 

 from the same locality measures: Total length, 769; head and body, 

 395; tail, 374; hind foot, 57; ear, 54. Skull: Six adult male skulls 

 measure as follows: Total length, 110.5 (102-122); basal length, 

 102.4 (92-118); nasals, 53 (45~57-5); zygomatic breadth, 59.5 (58- 

 64); postorbital breadth, 24.2 (23-28); postorbital constriction, 11.5 

 (11-12); occipital breadth, 33.8 (31-35.5); breadth at canines, 21.8 

 (19-25); upper toothrow, 35.5 (34-S-3 6 ) \ molar series, 19.4 (19-20). 



Specimens examined: 



Peru: Eten and Piura, Depart, of Piura, 8 specimens; coll. Brit. 

 Museum. 



Ecuador: Puna Island, 2 specimens; Guayaquil, 2 specimens; St. 

 Javier, i specimen; Jambilar, i specimen; coll. Brit. Museum. 



Colombia: Boqueron, Chiriqui, 33 specimens; Boquete, Chiriqui, 5 

 specimens; coll. Amer. Mus. and J. H. Batty. 



Total, 52 specimens. 



The above description is based on a series of 14 specimens, 

 of which 7 are from Eten, Peru, two from Puna Island, and 

 three from neighboring coast localities in Ecuador. In size 

 they greatly exceed the series of cauca from Cali, Colombia, 

 and have the incipient face markings better defined. The 

 tail about equals the head and body in length, as in that 

 form. The total length of the animal, however, is about 

 one eighth greater in etensis than in caucce, and the length of 

 the skull is also much greater 110.5 mm - as against 102.5 

 in cauc&. In size it approaches D. m. richmondi from Nicara- 

 gua, which, however, is not only much larger than etensis 

 but has a relatively much longer tail, in etensis the length of 

 the tail being a little less than that of head and body, and in 

 richmondi considerably more than the head and body length. 



A large series from the Department of Chiriqui, State of 

 Panama, Colombia, is similar in size and proportions, and is 

 not apparently distinguishable. This series includes 33 speci- 

 mens from Boqueron, and 5 from Boquete, of which measure- 



