Jjferriam 2few M'tnmml* front Oozwnel Island. 103 

 Peromyscus cozumelae sp. nov. 



Type from Co/umel Island, Yucatan, No. 108,449, $ ad., U. S. National 

 Museum, Biological Survey Collection. April 11, 1891, E. "W. Nelson 

 and E. A. Goldman. Original Xo. 14,686.' 



Character*. Size and tail medium; ears rather large, thin; color dull 

 brown or brownish fulvous: general appearance similar to P. affinis Al 

 len,* but slightly larger and somewhat darker and more uniform in 

 color. 



Color. Head and upperparts varying- from grayish brown to dull ful 

 vous brown: underparts white, the plumbeous underfur showing through; 

 tail indistinctly bicolor, brownish dusky above, pale yellowish or whitish 

 below (nearly naked): ankles and wrists brownish or dusky; fore and 

 hind feet whit islr. 



Cranial c/Hinn-f <-/*. Skull of medium size, with rather spreading zygo 

 mata, strongly set out and angled anteriorly: nasals broad, flattened, 

 ending about on plane of premaxillsB; incisive foramina rather large and 

 open. 



Remark*. Pgromyteu* cozumela 1 appears to have no very close relative. 

 Externally it resembles P. affinix Allen, but is darker and has thinner 

 ears and shorter tail. Cranial ly, however, it differs materially from any 

 species known to me. Compared with ajfitiia it may be distinguished by 

 the broader and more squarely elbowed zygomata, flatter and broader 

 braincase, broader nasals, slightly larger bullne, and heavier teeth. The 

 incisive foramina show considerable variation. In most specimens they 

 are long and their outer borders are evenly convex. In others they are 

 much more broadly open and the outer border forms an angle at the 

 maxillo-premaxillary suture. In some specimens they are rather short. 



Mfaxiireim-ntx. Type specimen ((^ad.): total length 180; tail vertebrae 

 SO: hind foot 2H. Average of 8 males from type locality: total length 

 181: tail vertebra* 82: hind foot 23.5. 



Oryzomys cozumelae sp. nov. 



Type from Cozumel Island, Yucatan. No. 108,462, tf ad., U. S. Na 

 tional Museum. Biological Survey Collection. April 8, 1901, E. W. Nel 

 son and E. A. (ioldman. Original Xo. 14. <>(>(>. 



C/ttit'ni'fi'i'ti; Size large: similar to O. atiuatn-n* Allen, but darker; 

 ears and hind feet larger: tail much longer and darker. 



Color. Upperparts dark grayish bister with pale fulvous suffusion on 

 sides and rump: in old pelage back (especially rump) rusty red; under- 



*Mv Peromyxcu* musculoidex (Proc. Biol. Soc. Wash., Vol. XII, p. 124, 

 .April 30, 1898) appears to be at most only a subspecies of P. affinis Allen, 

 from which it differs in slightly larger size, larger ears and longer ros 

 trum. 



