96 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 69 



Spines or bristles mixed with slender hairs much as in the unrelated 

 genus Heteromys. This genus is one of those whose occurrence 

 within our limits was disclosed during the field work in connection 

 with the present investigations. 



NEACOMYS PICTUS Goldman 



Fainted Bristly Mouse 



[Plate 23, figs. 2, 2a] 



Neacomys pictus Goldman, Smiths. Misc. Coll., Vol. 60, No. 2, pp. 6-7, 

 September 20, 1912. Type from Cana, eastern Panama (altitude 1,800 

 feet). 



This handsome little mouse is one of the smaller rodents of the 

 region. The pelage of the upperparts is composed of grooved black- 

 tipped spines or bristles and slender orange rufous hairs. The mouse 

 is easily recognized by the bristly pelage, rich orange rufescent 

 coloration, and the absence of the external cheek pouches present in 

 Heteromys. 



The adults present remarkably slight variation in size or color, the 

 orange rufous hairs mixed with the black-tipped spines producing 

 a uniformly grizzled effect over the upperparts. The underparts 

 are white, the color changing abruptly below a sharp ochraceous 

 buffy line of demarcation along the sides. A half-grown young 

 individual is in a comparatively soft pelage corresponding to the 

 immature coat seen in Heteromys and other genera. 



The species seems to be related to N. pusillus from the coast 

 region of western Colombia, but is a larger animal with white instead 

 of yellowish feet. The specimens were trapped in grass and small 

 bushes growing among rocks along the edge of a sugar-cane field at 

 1,800 to 2.000 feet elevation on a steep mountain side near the Darien 

 gold mines. Anthony (1916, p. 369) records the species from a 

 slightly higher altitude, 2,650 feet at the village of Tacarcuna and 

 remarks : " The genus was not encountered elsewhere." 



Specimens examined: Cana (type locality), 5; Tacarcuna, 2.^ 



Genus ORYZOMYS Baird. Rice Rats 

 The genus OrycoDiys seems to occupy in South America the place 

 filled in North America by the genus Peromyscus, as the Murine 

 group including the greatest number of species. But from South 

 America Oryzomys pushes northward through Middle -.\nierica, con- 

 siderably overlapping the range of Peromyscus. In this genus the 

 size is very variable, some forms being so small and slender that in 



* Collection Amer. Mus. Nat. Hist. 



