202 Mr. O. Thomas on small Mammals 
6. Euneomys micropus alsus, subsp. 0. 
g. 171, 177, 183, 188, 201, 202. Maiten, W. Chubut. 
700 m. 
Similar in all essentials to true HZ. micropus, as represented 
by series from Koslowsky (lat. 46° 8.) and Rio Chico, but 
almost or quite without the strong buffy suffusion on the fur, 
the general tone being more slaty greyish. Under surface 
also clearer greyish, with but little buffy wash. 
Dimensions of the type (measured in the flesh) :— 
Head and body 123 mm.; tail 117; hind foot 27; 
ear 18. 
Skull: greatest length 31°3 ; condylo-incisive length 28°7 ; 
zygomatic breadth 18; palatal foramina 7:8; upper molar 
series 5°7. 
Hab. as above. 
Type. Adult male. B.M. no. 18. 12.2.13. Original 
number 177. Collected 23rd April, 1918. 
The series with which these specimens have been compared 
includes specimens killed in February, June, August, and 
December, so that the difference in the general colour is 
evidently not a seasonal one. 
I may note here that my reference of Mus (Phyllotis) 
xanthopygus, Waterhouse, to the genus Huneomys—a refer- 
ence probably induced by the noticeable resemblance it bears 
to 2. micropus—now proves to be erroneous, as it is certainly 
a Phyllotis, the most southern member of that widely distri- 
buted genus. Its narrow incisors readily distinguish it from 
E. micropus, with which it is found. 
The local modification in colour shown by this subspecies 
is exactly as in the Abrothrix suffusus of the same region, 
7. Eligmodontia morgani, All. 
gf. 142/159) 165, 166); 912125, 154, 157; 160, 161,163, 
164. Pilcafieu, Upper Rio Negro. 
“Common. lives in holes at the foot of the bushes.’”— 
LB. 
8. Abrothrix suffusus modestior, subsp. n. 
@. 176, 182,198, 920555204, 211, 214, 217; ogee 
Maiten. 
Like typical sugfusus of ths Koslowsky region, but rather 
darker and more slaty grey, the reddish or buffy of the back 
reduced both in extent and brightness. Face almost without 
buffy. Sides quite without buffy, so that there is a broad 
