614 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.59. 



4. DESCRIPTIONS OF THREE SUPPOSED NEW SPECIES OF RODENTS 

 OF PLEISTOCENE AGE, ONE FROM NEBRASKA, ONE FROM OREGON, 

 AND ONE FROM TEXAS. 



Through the liberality of the American Museum of Natural History, 

 New York, the writer has been permitted to study the collections of 

 vertebrate remains of Pleistocene age which that institution possesses. 

 Among the remains sent are parts of the Cope collection, made at 

 different localities; also some specimens collected by expeditions 

 sent out by the American Museum itself. 



Of especial importance is the large collection made by Mr. Barnum 

 Brown in the Conard fissure, in Newton County, Arkansas, in 1903 

 and 1904. Of interest, too, is a small collection made by Mr. Brown 

 in a cave at Anita, Coconino County, Arizona, in 1904. In the study 

 of the materials mentioned the writer has found what appear to be 

 three new species of Glires. The following are the species: 



THOMOMVS SCUDDERI, new species. 



Plate 120, figa. 1-4. 



Type specimen. — Skull with the incisors and molars, but lacking 

 most of the part behind the f rontals ; the lower j aw with its teeth ; a 

 few vertebrae; the pelvis and some limb bones. No. 8596, American 

 Museum of Natural History, New York; a part of the Cope collection. 



Type locality. — Christmas Lake, Oregon. 



Type formation. — Pleistocene. 



Diagnosis. — Animal of medium size. Lower outline of rostrum 

 straight to near the incisors. The latter grooved and incurved some- 

 what more than in T. oottae leucodon, but not projecting so far beyond 

 the bone. Interorbital space flat, the ridges inconspicuous, and 

 forming a lyriform figure on the frontals. 



In studying these fossil remains the species that first suggested 

 itself for comparison is that now living in the region of Christmas 

 Lake, Tlwmomys quadratus Bailey. 8 A slight examination shows, 

 however, that the fossil does not belong to T. quadratus. A com- 

 parison with materials in the United States National Museum and in 

 the Biological Survey has led the writer to regard the remains as 

 being somewhat closely related to T. oottae leucodon. 



This subspecies ranges to-day from Cape Saint Lucas to Grants 

 Pass, in southwestern Oregon. It has incisors which are slenderer 

 than those of the fossil. A specimen in the National Museum (Mamm. 

 Cat. No. 4783) measures, from the rear of the frontals to the incisive 

 border, in front of the incisors, 26 mm. This is the same as in the 

 fossil skull. The interorbital space in the former is 7 mm. wide; in 

 the fossil, 7.5 mm. the width of the rostrum in the former is 7 mm. ; in 



»N. A. Fauna, 139, pp. 23, 114, text fig. 3. 



