Mammals from Peru and Bolivia. 185 
contributed some additional specimens from Caylloma. These 
localities show that the species ranges over a quadrangular 
area some 200 miles each way between about 69° and 72° W. 
and 13° and 16° 'S. 
But the specimens from the different localities are not all 
identical, falling into four fairly separable subspecies, those 
from Sumbay being apparently typical, while each of the 
other places above mentioned has its own local form. 
All are, however, so alike in general characters and agree 
so closely with the original description that there is no need 
for a detailed account of each, the differential characters and 
the dimensions being alone given. 
1. Akodon pulcherrimus (typical). 
Back fuscous brown, not darkening laterally, the sides if 
anything paler than the back. White ear-patch large, ex- 
tending backward beyond the ears when these (dry) are folded 
back, continuous below with the white of the under surface, 
or, rarely, with a faint darker wash separating the two. 
Hab. Puno (Kalinowsk?); Sumbay, near Arequipa (Simons). 
Alt, 4000 m. 
Average measurements of five specimens from Sumbay :— 
Head and body 89°8 millim. ; tail 72°8; hind foot (s. u.) 23; 
ear 19. 
2. Akodon pulcherrimus cayllome, subsp. n. 
Like the typical form as to general colour and ear-patch, 
but the sides darkening instead of lightening as they approach 
the white of the belly, so that an indistinct blackish line is 
formed edging the clear white of the belly. 
Dimensions of the type (taken in the flesh) :— 
Head and body 94 millim.; tail 82; hind foot 23; ear 20. 
Average measurements of four adults : Head and body 91°7 ; 
tail 75°2 ; hind foot (s. u.) 22°2; ear 19°5. 
Hab. Caylloma. Alt. 4300 m. 
Type. Female. B.M. no. 0. 10. 1. 74. Collected 14th 
June, 1900, by Mr. P.O. Simons. Six specimens examined, 
of which Mr. Simons obtained four and Mr. Hunt two. 
‘'wo young specimens show the dark lateral marks parti- 
cularly well. 
3. Akodon pulcherrimus tnambarii, subsp. n. 
Like the typical form as to colour, but the light ear-patch 
is so much reduced that the laid-back ears surpass it poste- 
