196 Mr. 0. Thomas on ike South- American 



Species and subspecies : — 



al forum, All. 

 aureus, Tomes. 

 baops, TJios. 

 ctncreiventer, All. 

 daphne, Thos. 

 gracilis, Thos. 

 hylophiliis, Osg. 

 ischxjrus, Osg. 

 halinowskii, Thos. 

 latiiger, Thos. 

 mucconnelli, de Wint. 



monochrotnos, Bangs. 

 niveipes, Thos. 

 notatus, Thos. 

 2Mramormn, 'I'hos. 

 2)opa)/umis, All. 

 prcetor, Thos. 

 princeps, Thos. 

 jryrrlionutus, Thos. 

 rhoadsi, Stone. 

 taczanowskii, Thos. 

 vestitus, Thos. 



3. Pn.ENOMYs, geu. nov. 



Form normal. Tail short-haired. Claws slender^ not 

 specially curved. Mammae 2 — 2 = 8. 



Skull slender, of normal proportions. Interorbital region 

 sliglitly concave, its edges forming definite raised, headings, 

 continued backwards across the parietals. 



Incisors rather heavy. M^ not so evenly oblong as in the 

 other genera, the antero-internal cusp more definitely 

 reduced. 



Range. South-eastern Brazil (Bahia, Rio Janeiro). 



Genotype and only species. Phaenomys Jerruyineus, Thos. 

 ( Oryzomys ferrugineus, Thos.) . 



4. Delomys, gen. nov. 



Form normal. Tail quite sliort-haired, about as in 

 Oryzomys. Claws normal. Mammae 2 — 2 = 8 iu two speci- 

 mens of 2). dorsalis from Rio Grande do Sul, 1 — 2 = 6 in one, 

 believed to represent a new subspecies, from Rio Janeiro. 

 The latter number may be an abnormality. 



Skull long, with long heavy muzzle and small brain-case. 

 Interorbital region rather broad, smooth, its edges rounded, 

 or slightly squared, not ridged or beaded. Zygomatic plate 

 projected forwards above far enough to be seen from above, 

 that of all the other forms mentioned in the present paper 

 absolutely without projection. 



Molars rather narrow. M^ evenly oblong. 



Range. South-eastern Brazil, from Espiritu Santo to Rio 

 Grande do Sul. 



Genotype. Delomys dorsalis Hens. (Hesperomys dorsalis, 



Hens.). 



Other forms : — " Oryzomys^'' sublineatus^ Thos. and a new 

 subspecies of dorsalis described below. 



