ao8 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. X. 



P. domorum. In fact it seems necessary to include the species amicus 

 as a peripheral member of the group Graomys and to recognize its 

 connectant character by treating that group as a subgenus co-ordinate 

 with typical Phyllotis. 



Akodon puer Thomas. 



One specimen, Parotani. 



This specimen agrees closely with the original description of A. 

 puer, the principal discrepancy being in the color of the ears which are 

 mixed grayish and dusky in some contrast to the body color. Flesh 

 measurements are: Total length 169; tail 75; hind foot 20. 



Akodon varius Thomas. 



One specimen, Parotani. 



Although comparison with the type from Cochabamba would be 

 desirable, there seems little reason to doubt the identity of this speci- 

 men, especially since Thomas in the original description has referred to 

 another from this locality. Flesh measurements are: Total length 203; 

 head and body 108; tail 95; hind foot 26. 



Akodon dayi sp. nov. 



Type from Todos Santos, Chapare* River, Bolivia. No. 21329 Field 

 Museum of Natural History. Adult male. Collected March isth, 

 1915 by Robert H. Becker. Original No. 784. 



Characters. A medium-sized species of dark, rich, color. Somewhat 

 allied to A. cursor but very much darker with larger hind feet and a 

 heavier and decidedly deeper skull. Similar in color to A. aerosus 

 baliolus, but under parts paler and more heavily washed with fulvous; 

 cranial characters widely different. 



Color. Upper parts varying from Vandyke brown to burnt umber; 

 middle of back scarcely or not at all darker than sides; under parts rich 

 rufous; ears blackish without mixture of fulvous; feet brownish black; 

 tail blackish above and below. 



Skull. As compared with that of A. aerosus, the skull is long and 

 high, both incisor and molar teeth are heavier, and the braincase is 

 narrower; the supraorbital edges are sharp and continuous with a 

 definite ridge which crosses the parietals to the occipito-squamosal 

 suture, where it turns abruptly downward and becoming more decided 

 forms a sharp vertical ridge to the mastoid bulla; the occiput scarcely 

 projects beyond the vertical plane of the back of the interparietal which 

 is often sharp-angled behind, forming with the supraoccipital a definite 

 inion; the zygomatic plate is broad and nearly vertical or slightly con- 



