276 



OBSERVATIONS ON THE RODENTIA. 



tine portions of the intermaxillary, maxillary, and palatine 

 bones are all on the same plane, and the posterior margin. of 

 the latter is almost always situated behind the line of the pos- 

 terior molars. The incisive foramina are large, and situated 

 partially in the intermaxillary, and partly in the maxillary 

 bones. There are two moderately large foramina in the pa- 

 lato-maxillary suture. 



Lower jaw. — The eoronoid process is usually large, and 

 the condyloid elongated : the descending ramus approaches 

 more or less to a quadrate form ; the posterior lower angle is 

 rounded, and the upper angle is acute. 



35 



(o and b) Psammomys obesus. (c) Gerbillus brevicaudatus. {d) GerbiUus Indicus 



(c) anterior part of the skull of Cricetus auratus. (/) side view of the same. 



In the form of the lower jaw the Muridce do not differ es- 

 sentially from the preceding families, the skull however is of 



