Vol. XVII, pp. 53-54 • MaSch 21, Id04 



PROCEEDINGS 



OF THK 



BIOLOGICAL SOCIETY OF WASHINGTON 



HAPLOMYLOMYS, A NEW SUBGENUS OF PEROMYSCUS. 

 BY WILFRED H. OSGOOD. 



The genus Peromyscns, as at present recognized, contains a 

 larger number of species than any other North American genus 

 of mannnals. It has a comparatively wide range, and, although 

 subject to numerous minor variations, preserves its essential 

 characters with remarkable uni- 

 formity. Thus far only two sul)- 

 generic names have been proposed 

 for subordinate groups within the 

 genus — Baiomys, erected b}' True 

 in 1894* for the tiny species P. 

 taylorl, and Megadontomys, {)ro- 

 posed V)y Merriam in 1898 f f<>i' 

 the largest species of the genus 

 P. thoiiKisi Both of these are well 

 characterized, but represent aber- 

 rant types rather than assem- 

 blages of species. Baiomys con- 

 tains only two well-marked s\)e- 

 cies (each possibly divisil)le into 

 several sul)species) and Meyadoa- 

 tomys is represented by only the 

 type species and two closely re- 

 lated forms. All the other species are at present retained in 



Fig. 1. — A. Upper molars of Peromi/sciis 

 ( Pcromyscus) felipensts. B. Upper mo- 

 lars ot Peromyscus (Haploinyloiiiys) cnli- 

 fornicus. (About X 9/^). 



*Proc. U. S. Nat. Mus., XVI, p. 758, 1894. 



tProc. Biol. Soc. Wash., XII, pp. 115-116, April 30, 1898; see also 

 Bangs, Bull. Mus. Comp. Zool., XXXIX, p. 27, 1902, where Megadontomys 

 is given generic rank. 



0— Puuf. Blui.. Sue. Wash. Vol. XVII, 19(14 



(53) 



