ARBOREAL RICE RATS — HERSHKOVITZ 519 



Oryzomys concolor superans Thomas (p. 556). 

 Oryzomys concolor roberti Thomas (p. 559). 



Oryzomys concolor bahiensis, new subspecies (replaces Mus cinnamomeus 

 Pictet and Pictet, preoccupied) (p. 561). 



Status of Certain Species Incorrectly Assigned to Oecomys 



Oecomys catherinae Thomas, 1909= Oryzomys subflavus Wagner, 1842. 

 (See infra p. 543.) 



Oecomys rex Thomas, 1910 = Oryzomys subflavus Wagner, 1842. (See 

 infra p. 543.) 



Oecomys emiliae J. A. Allen, 191Q= Rhipidomys emiliae J. A. Allen. 



Oecomys phelpsi Tate, 1939= Akodon aerosus Thomas, 1913. The 

 name phelpsi is based on a skin of what may be either an Oecomys 

 or a Rhipidomys (cf. Tate, Bull. Amer. Mus. Nat. Hist., vol. 76, 

 p. 194, 1939) and a mismatched skull of Akodon (Chalcomys) 

 aerosus. The name phelpsi was restricted to the skull by Tate 

 (Journ. Mammal., vol. 26, p. 316, 1945). Oecomys phelpsi Tate, 

 therefore, is a synonym of Akodon aerosus. Goodwin (Bull. 

 Amer. Mus. Nat. Hist., vol. 102, p. 300, 1953) lists the skin as 

 type, Tate's decision, however, has priority and is irrevocable. 



Mus pyrrhorhinos Wied Neuwied, 1821 = Wiedomys pyrrhorhinos 

 Wied Neuwied. This small arboreal mouse from eastern Brazil 

 was provisionally referred to Oecomys by Osgood (Journ. Mam- 

 mal., vol. 14, p. 370, 1933) and is so classified by Goodwin (Bull. 

 Amer. Mus. Nat. Hist., vol. 102, p. 300, 1953). EUerman (Fami- 

 lies and genera of living rodents, vol. 2, p. 349, 1941) lists it as 

 the sole member of a species group of Oryzomys. It has since 

 been shown (Hershkovitz, Proc. Biol. Soc. Washington, vol. 72, 

 p. 5, 1959) that the mouse is type of a distinct genus most nearly 

 related to phyllotine rodents. 



Mus maculipes Pictet and Pictet, 184l4l= Rhipidomys maculipes Pictet 

 and Pictet. Incorrectly listed as an Oecomys by Tate, Amer. 

 Mus. Nov., No. 581, pp. 10, 21 [footnote 1], 1932. 



Hesperomys simplex Winge, 1888 = ? Winge (E Museo Lundii, vol. 1, 

 No. 3, p. 11, pi. 2, fig. 1, 1888) based the name on the anterior 

 portion of a skull found in owl pellets in Recent-Pleistocene de- 

 posits in the caves of Lag6a Santa, Minas Gerais, Brazil, Moojen 

 (Os roedores do Brasil, p, 55, 1952) treats this species as an 

 Oecomys. However, it is obvious from the original description 

 and figured skull, and from Winge's own definition of Hesperomys, 

 that simplex is neither an Oecomys nor an oryzomyine. The 

 broad forward-projecting zygomatic plate of simplex, its narrow, 

 unridged, and rather concave-sided interorbital region, long 

 palate, and simplified molars, i.e. without mesoloph, point to 



