COUES ON GEOMYS AND THOMOMYS OSTEOLOGY. 
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and arched anteriorly ; molars far 
below level of zygomata. 
Incisors large, parallel-edged, scarcely 
converging. 
Anterior molar, a double prism. 
Root of inferior incisor protuberant 
posteriorly. 
Large erect falcate coronoid, overtop 
ping condyle. 
&c., &c. 
horizontal ; molars on a level with 
the zygomata. 
Incisors small, acuminate, conver 
gent. 
Anterior molar, a single prism. 
Root of inferior incisor not promi 
nent posteriorly. 
Minute prickle-like sloping coronoid, 
far below level of condyle. 
&c., &c. 
