BANGS: CHIKIQUI MAMMALIA. 37 



Zygodontomys cherriei (Allen). 



One youngish 9 , Bogaba, July 3. 



I have compared this example with topotypes, kindly loaned by Dr. Allen, 

 and can find no differences. The type locality of the species is Boruca, Costa 

 Rica, in the low lands. 



The present specimen, not full grown, measures, total length, 195 ; tail ver- 

 tebrae, 75 ; hind foot, 23; ear, 13. 



Zygodontomys chrysomelas (Allev). 



Three specimens, Bogaba, July. 



It is possible that the Chiriqui form may prove to be subspecifically different 

 from true Z. chrysomelas of Costa Rica (type locality Suerre). One specimen 

 loaned by Dr. Allen from San Carlos, differs from the Bogaba examples in 

 being smaller, with smaller skull, lighter rostrum, and broader palatal slits. 

 Additional material, however, may show these differences to be individual. 



The Vesper rats, related to Z. chrysomelas, of which there are several in 

 South America, form quite a distinct group in the genus Zygodontomys, dif- 

 fering from the more typical members, in their very dark coloration, reddish 

 bellies, nearly naked, dusky feet and hands, -with white nails, and in their 

 wider skulls — especially w^ide between the orbits — %vith strongly marked, over- 

 hanging superciliary beading. 



Measurements (of the three Bogaba skins) — 



Ear. 



14 



Reithrodontomys australis Allek. 



Two specimens, adult $ and 9 , Boquete, 4,000 feet, April 30. 



These I have compared -with the type of R. australis from Volcan de Irazii, 

 Costa Rica, loaned by Dr. Allen. In color they exactly agree, except that the 

 upper siuface of the feet is darker, more grayish — the feet being whitish in 

 the type. The skulls of the two Boquete specimens, are heavier throughout 

 especially the rostral part, and in this character they are intermediate between 

 true R. australis and the form described below from the summit of the Volcan 

 de Chiriqui. 



Measurements (of the two Boquete skins) — 



