BANGS: CHIRIQUI MAMMALIA. 33 
Color. — Upper parts cinnamon brown darkened along middle by the ad- 
mixture of dark brown tipped hairs, somewhat shaded with russet on rump and 
flanks; under parts white washed with pale buff, sharply contrasted against 
color of upper parts ; ears dusky with some hairs on both surfaces colored like 
those of the back; feet and hands yellowish gray (much paler than in S. 
boruce), tail thickly clothed with short, stiff, close hairs, dusky above, gray 
below. 
Measurements. — Type, adult @, total length, 260; tail vertebre, 120; hind 
foot, 32 ; ear, 17. 
Skull (an adult with somewhat worn teeth; unfortunately it was broken 
by the trap directly across between the orbits) — mastoid width, 14.8 ; upper 
molar series, 6; length of single half of mandible, 19.2. 
Remarks. — The Sigmodon of the low lands of Chiriqui is a small dark col- 
ored species with very soft pelage, that I cannot distinguish from S. boruce of 
the low lands of Costa Rica. 
When Dr. Allen described that animal he spoke of specimens from San 
José 5,000 feet altitude, that had hispid pelage, but otherwise did not differ. 
The one example from the top of the Volcan de Chiriqui, differs from S. 
boruce of the adjacent low lands not only in having much more hispid pelage, 
a much paler coloration throughout, but also a longer tail. 
In the forest belt of the Volcan, where Mr. Brown did much trapping, he 
did not find Sigmodon, and for that reason I give full specific rank to the form 
of the summit of the Volcan de Chiriqui. It has been my experience that 
Sigmodons love open fields, savannahs, brushy places, and waste land, and 
avoid the dense forest. 
Oryzomys alfaroi (ALLEY). 
Fourteen specimens, Boquete, 4,000 feet, February and April; Divala, 
December. 
I have compared this series with specimens from Tins, Costa Rica (the type 
locality of the species is San Carlos, Costa Rica) sent me by Dr. Allen, and can 
detect no differences. 
Measurements (of six adults from Boquete) — 
No. Sex. Total length. Tail vert. Hind foot. Ear. 
10,315 2 235 120 26 16 
10,322 ga 295 110 26 16 
10,311 & 225 105 26 15 
10,314 o 215 105 23 15 
10,316 Wee: 215 110 26 15 
10,320 BS 210 105 25 15 
