Cope.] ^'^ [July 16, 



Tamias laevidens, Cope, sp. nov. 



This ground squirrel is indicated by the distal half of a mandibular 

 ramus, with adjacent fragments, probably of maxillary and squamosal. 

 The successional first molar appears above the alveolar border, and an- 

 other tooth apparently is in place, but so encrusted with calcite, as to be 

 quite obscured. 



This species differs in three marked peculiarities from the T. stri- 

 atus. The first molar has two anterior cusps instead of one ; they are 

 separated by a deep groove ; there is also a little cusp between the ex- 

 ternal two. The incisor teeth are not striate grooved on their anterior 

 face, as in T. st riatus, though they have three narrow grooves on the 

 outer longitudinal angle ; they are wax yellow anteriorly. Third, the 

 ramus is more slender, especially in the portion anterior to the molars ; 

 the depth at the mental foramen is just half the length between the first 

 molar and the base of the incisor above. As in T. striatus, this foramen 

 is nearer the superior outline of the ramus. There is less curvature visible 

 in the inferior face than in some individuals of the existing species. 



Llnss ■ 



Length ramus anterior to m. 1 2.G 



Depth at mental foramen 1.4 



'; " first tooth 1-7 



Diameter incisor 1. 



Depth at m. 4 2.2 



SciuRus PANOLiTJS, Gope, sp. nov. 



A small squirrel of the size of the Chipmunk (Tamias striatus), 

 but of the type of dentition and form of the Sciurus hudsonius. It is 

 represented by a ramus mandibuli, containing two molar teeth, and the 

 included portion of the incisor, the coronoid, and vertical ramus being 

 lost. Numerous fragments, including incisors, etc., are probably to be 

 referred to this s])ecies. 



The ramus is quite flat, being perfectly plane on the inner face, below 

 the molars ; its diameter below the first is equal to that at the incisive 

 alveolar margin above. The series of molars is very little oblique to the 

 plane of the ramus, and, judging by the positions of the anterior three, 

 not curved. There is, therefore, but a slight projection of the alveolar 

 border on the inner face of the ramus. The least depth of the edentu- 

 lous portion, equals the chord from the base of the first molar to the edge 

 of incisive alveolus. The mental foramen is near the middle of this 

 length, and a little above the middle of its depth. The anterior margin 

 of the masseteric fossa, is below the posterior third of the first molar. 



The two molars are well worn, the first being successional: the animal 

 was therefore adult. The worn faces are concave; the inner anterior 

 point of tlie margin is the most elevated, while the two external lobes are 

 in both the most prominent. There is also a slight emargination on the 

 inner face. The first molar is about as long as wide, the second a little 

 wider than long, and slightly oblique forwards and inwards; the inner 



