102 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 69 



Subgenus OLIGORYZOMYS Bangs 



ORYZOMYS FULVESCENS COSTARICENSIS Allen 



Costa Rican Pygmy Rice Rat 



Orysomys costaricensis Allen, Bull. Amer. Mus. Nat. Hist., Vol. 5, p. 329, 

 September 22, 1893. Type from El General, Costa Rica (altitude 2,150 

 feet). 



The Costa Rican pygmy rice rat is a very small form closely 

 resembling some species of Reithrodontomys from which it may be 

 easily distinguished in the flesh by the smooth instead of grooved 

 upper incisors. It differs from O. f. fulvescens of Mexico mainly 

 in the larger molar teeth, and from 0. f. vegetus of the Volcan de 

 Chiriqui in smaller size and usually paler color. 



Very few specimens have been taken in Panama and the subspecies 

 appears to be restricted to the savanna region from the Costa Rican 

 frontier eastward along the Pacific coast. Anthony (1916, p. 368) 

 records two specimens taken by him on the savanna near Old 

 Panama, and the range of the animal probably extends as far east as 

 Chepo. 



Specimens examined : La Chorrera, 1 1 ; Old Panama, 2. 1 



ORYZOMYS FULVESCENS VEGETUS Bangs 



Volcan Chiriqui Pygmy Rice Rat 



Orysomys (Oligoryzomys) vegetus Bangs, Bull. Mus. Comp. Zool., Vol. 39, 

 text fig. 15, p. 35, April, 1902. Type from Boquete, Volcan de Chiriqui, 

 Panama (altitude 4,000 feet). 



Larger average size and a tendency toward darker coloration 

 usually distinguish this small rice rat from O. f. costaricensis which 

 inhabits lower elevations. 



Five specimens collected by W. W. Brown, Jr., at 3,800 to 4,800 

 feet altitude near Boquete were referred by Bangs (1902, p. 35) to 

 O. /. costaricensis and 13 others from the same locality were at the 

 same time described by him as a new species, O. vegetus. 0. vegetus 

 Bangs was regarded as identical with costaricensis by Allen (1904, 

 p. 69), who says : " The type and 12 topotypes of O. vegetus kindly 

 sent me for examination by Mr. Bangs do not differ appreciably 

 from the type, three topotypes, and additional Costa Rican specimens 

 of O. costaricensis. They also agree with the seven Boquete speci- 

 mens collected by Mr. Batty, which I unhesitatingly refer to O. cos- 

 taricensis.'' The specimens assigned by Bangs to costaricensis are 

 rather pale and probably indistinguishable by color from many 



* Collection Amer. Mus. Nat. Hist. * 



