NO. 5 MAMMALS OF PANAMA — r.Of.DMAN 97 



the flesh they arc most easily distinguislied from Kcithrodontomys by 

 the smooth instead of grooved upper incisors ; others are as large as 

 common rats. Tlie short ears, usually harsh fur, and rather long, 

 thinly haired hind feet will aid in the recognition of the rice rats 

 among the numerous small rodents of the region. 



Subgenus ORYZOMYS Baird 



ORYZOMYS GATUNENSIS Goldman 



Gatun Rice Rat 



[Plate 24, figs. 2, 2a] 



Oryzomys s,alunensis Goldman, Smiths. Misc. Coll., Vol. 56, No. 36, p. 7, 

 February ig, 1912. Type from Gatun, Canal Zone, Panama. 



The Gatun rice rat is a member of the O. palustris group allied 

 to O. richmondioi Nicaragua, contrasted with which it is paler, more 

 grayish brown in color; the skull differs in detail, .the frontals 

 being decidedly broader with lateral margins more developed as 

 supraorbital shelves ; the interparietal is much less extended antcro- 

 posteriorly and the nasals are more prolonged posterioi^y beyond the 

 premaxilla?. 



The type and only known specimen is a young individual which 

 seems to require comparison only with O. richmondi. It was trapped 

 in an abandoned sugar-cane plantation on the bank of the Chagres 

 River, 



Specimens examined : Gatun, i (type). 



ORYZOMYS ALFAROI ALFAROI Allen 



Alfaro's Rice Rat 



Hesperomys (Oryzomys) alfaroi Allen, Bull. Amer. Mus. Nat. Hist., Vol. 3, 

 p. 214, April 17, 1891. Type from San Carlos, Costa Rica. 



Alfaro's rice rat is a small, slender, dark colored species which 

 ranges into western Panama from Costa Rica. It is closely allied to 

 0. a. daricnsis of the mountains of the eastern part of the republic. 

 Contrasted with that subspecies the present form is duller, less 

 rufescent in coloration. 



Specimens collected by W. W. Brown, Jr., at 4,000 feet altitude 

 near Boquete are recorded by Bangs (1902, p. 33). 



Specimens examined: Boquete, 14.' 



* Eleven in collection Mus. Comp. Zool. ; two in Field Mus. Nat. Hist.; one 

 in Amer. Mu». Nat. Hist. 



