NO. 5 MAMMALS OF PANAMA — GOLDMAN 51 



MARMOSA INVICTA Goldman 



Black Marmosa 



[Plate 21, figs. 2, 20] 



Marmosa invicta Goldman, Smiths. Misc. Coll., Vol. 60, No. 2, p. 3, Sep- 

 tember 20, 1912. Type from Cana, eastern Panama (altitude 2,000 feet). 



A blackish species of pygmy opossum, mouse-like in size and 

 superficial appearance, was discovered at Cana, in the mountains of 

 eastern Panama. The marsupial pouch is absent as usual in the 

 genus. The mammae in an adult female were enclosed in a cinnamon 

 brownish abdominal area. Examination before skinning showed the 

 mammae, five in number, irregularly placed, three being ranged in a 

 row on the right side, one on the left, and the other on the median 

 line. Two specimens only were obtained, both of them at the same 

 locality in traps placed among rocks in second growth forest. 



This species has no known near relative in Middle America, but 

 may be allied to some of the South American forms of the large 

 unrevised genus to which it belongs. 



Specimens examined : Two from the type locality. 



Genus METACHIRUS Burmeister 

 The members of this genus are of medium size, the pelage short, 

 rather straight, without the projecting bristles present in Didelphis, 

 and lacking the long lax woolly quality of the pelage of Philander. 

 With advancing age the temporal ridges unite to form a high, trench- 

 ant sagittal crest similar to that developed somewhat earlier in 

 Didelphis. Two species range into Panama. 



METACHIRUS OPOSSUM FUSCOGRISEUS Allen 



Allen's Opossum; Zorro 



Metachirus fuscogriscus Allen, Bull. Amer. Mus. Nat. Hist., Vol. 13, p. 194, 

 October 23, 1900. Type locality, Greytown, Nicaragua. 1 



Of the several species of opossums inhabiting the region this form 

 is by far the most abundant at low elevations. It is about the same 

 in size, and in general appearance resembles its Panama congener, 

 Metachirus nudicaudatus dentancus, by which it is largely replaced 

 on the upper slopes of the mountains. It differs, however, in dark 

 grayish instead of brownish general coloration, and the light mark- 

 ings on the head are grayish instead of ochraceous buffy. The two 



Type locality fixed by Allen, Bull. Amer. Mus. Nat. Hist., Vol. 30, p. 247, 

 Dec 2, 1911. 



