BANGS: CHIEIQUI 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 bufl", 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. 

 borucce), tail thickly clothed with short, stiff, close hairs, dusky above, gray 

 below. 



Measurements. — Type, adult ^, total length, 260; tail vertebrae, 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. borucce of 

 the low lands of Costa Rica. 



When Dr. Allen described that animal he spoke of specimens from San 

 Jose 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 5. 

 borucce 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 Yolcan, 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 (Allen). 



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) — 



