LEPUS CUNICULUS 



279 



which is broad, long and curved and the posterior immediately 

 behind it is rounder, smaller and less curved. The enamel layer 

 is more strongly developed on the front than on the hinder edge 

 of the anterior incisor, with the result that use keeps it sharpened 

 as the hinder edge wears away quicker than the front, always 

 preserving a chisel-like cutting surface. A long narrow continuation 

 of the premaxilla, the nasal process, runs backwards alongside the 

 nasal bone. The space left on the ventral side of the nasal capsule 

 between the premaxillae is in part filled by two median ventral 



PP 



Tb. 



FIG. 91. Lepus. Lateral view of skull. - 



A., superior incisor ; B., inferior incisor ; C., nasal ; D., pre-maxilla ; E., mandible ; F., angle 

 of mandible ; G., zygomatic process of maxilla ; H., frontal ; I., parietal ; I.F., infra-orbital 

 foramen ; J., squamosal ; Ju., jugal ; K., interparietal ; L., supra-occipital ; La., lachrymal ; 

 M., optic foramen ; MX., maxilla ; N., external auditory meatus ; O.C., occipital condyle ; P.P., 

 paroccipital process ; Pr., premolar ; T.B., tympanic bulla. 



backwardly running plates, the palatine processes, one from each 

 premaxilla. At the hinder end the two nasal cavities are separated 

 by a complete bony plate coming from the mesethmoid bone (c) and 

 termed the septum narium ; this is continued in the living animal, 

 to the front end of the cavities as a cartilaginous lamina which is 

 generally absent in prepared skulls. Practically the whole of the 

 nasal cavity on each side is filled by a number of extremely delicate 

 much coiled bones, the turbinals (c), termed the ethmo-turbinals, 

 maxillo-turbinals or naso-turbinals according to the bone to which 

 they are attached. Much of the wall of the postero-lateral and 

 postero-ventral regions of the olfactory capsule is completed by 

 processes of the maxilla (m) proper, the main mass of which, how- 

 ever, lies in the cranial region. 



