1 90 1.] Allen, New Opossums of the Genus Metachirus. 2'I 5 



Metachirus fuscogriseus pallidus, subsp. nov. 



Type, No. 58158, U. S. Nat. Mus., $ adult, Orizaba, Vera Cruz, Mexico, 

 June 24, 1894. Collected by E. W. Nelson and E. A. Goldman. 



Similar to M. fuscogriseus, but the coloration is much lighter, the eye spots 

 are larger, and the black of the head less intense and more restricted in area pos- 

 teriorly ; size and proportions apparently the same as in fuscogriseus. 



Measurements. Type : Total length, 627 ; head and body, 315 ; tail, 312 ; 

 tarsus, 47 (collector's measurements in the flesh). The skin measurements show 

 different proportions. While the total length is the same as above given, the 

 length of the head and body is 310, and of the tail 317, which would give about 

 the normal tail ratio. For further measurements see table of measurements 

 below. 



Skull. The skull presents no appreciable difference from skulls of corre- 

 sponding age of M. fuscogriseus from Nicaragua. The measurements of the 

 type skull are as follows : Total length, 77 ; basal length, 1 69 ; length of nasals, 

 37 I zygomatic breadth, 39 ; postorbital processes, 14.3 ; postorbital constric- 

 tion, 9 ; mastoid breadth, 25 ; palatal length, 42 ; palatal breadth at mm 4 

 (including teeth), 22.5; upper toothrow, 27; upper molar series, 15. The 

 specimen selected for type is much above average size, as shown by the measure- 

 ments tabulated below. 



EXTERNAL MEASUREMENTS. 



1 From posterior base of incisors to front border of foramen magnum. 



