Neotropical Mammals. 1(37 



middle, the middle part projecting outwards on each side in 

 an angle at the premaxillo-maxillary suture. Posterior 

 narial opening narrow, the notch sharply V-shaped. Teeth 

 narrow throughout, the fifth maxillary tooth Q'2 x4-2 mm. 



Dimensions of the type (as taken by collector in the 

 flesh) :— 



Head and body 410 mm. ; tail 230. 



Cephalic shield 116 x 78. 



Skull : back of frontals to end of nasals 85 ; greatest 

 breadth 64; nasals, length 40, breadth, anteriorly 11, in 

 middle 19, posteriorly 12*5 ; palatal length 64 ; breadth of 

 palate between fifth maxillary teeth 13' 3. 



Jlah. Tapia, Tucuman. Alt. 700 m. 



Ti/pe. Adult male. B.M. no. 3. 6. 6. 16. Original num- 

 ber iyiO. Collected 23rd September, 1902, by L. Dinelli ; 

 presented by Oldfield Thomas. Two specimens examined. 



Marmosa chloe, sp. n. 



A small dark-coloured species, with creamy cliest and 

 inguinal region. 



Size about as in M.fuscata, Thos., and M. Klagesi, All. 

 Fur soft and fine; hairs of back about 6 mm. in length. 

 General colour above sepia along the dorsal area, shading off 

 into bistre on the sides. Under surface, on throat, chest, and 

 inguinal region^ pale pinkish or creamy buff, the hairs this 

 colour to their bases ; but on the belly the slaty-based hairs 

 encroach on each side, so as to narrow the creamy part to a 

 mere median line. Sides of face with a large ill-defined 

 black patch surrounding the eyes, the paler area between 

 them less marked than in Klagesi. Lower cheeks cream-buff. 

 Ears naked, dark grey. Hands pale brown, feet whitish. 

 Tail with its short-liaired part about half an inch in length, 

 the remainder naked, uniformly pale grey. 



Skull shaped very much as in M. Klagesi ; similarly 

 broad, with expanded zygomata and fairly well defined supra- 

 orbital ledges. Nasals expanded posteriorly. 



Dimensions of the type (measured in the flesh) : — 



Head and body 143 mm. ; tail 170 ; hind foot 21 ; ear 19. 



Skull : greatest length 33-7 ; basal length 30 ; greatest 

 breadth 18; nasals 14x4; interorbital breadth 5*2 ; breadth 

 of brain-case lo'O; palate, length 18"2, breadth outside 

 m^ 10*5 ; combined length of three anterior molariform 

 teeth 5'6. 



llab. Demerara Eiver, 29 miles above Georgetown, British 

 Guiana. 



