842 



KODENTIA 



SJiiiIl. — The skull differs conspicuously from that of all other 

 European Murime in the striking contrast between the short 

 weak I'ostrum and the large, much elongated brain-case ; distance 

 from upper border of infraorbital foramen to tip of nasal less 

 than one-third that from foramen to posterior border of occiput, 

 while in other members of the sub-family it is nearly one-half. 

 Dorsal i:)rofile gradually rising and nearly straight from tip of 

 nasals to interorbital region (sometimes with a faint angle at 

 middle of nasals), then broadly convex, slightly more gradually 

 anteriorh^ than posteriorly, to interparietal, where a slight 

 bi-eak in the j^rolile is produced by the more abrupt convexity 

 of the overhanging posterior portion of brain-case ; ventral 

 profile without sjsecial features, essentially straight from incisor 

 to condyle, except for the slight break caused by the auditory 

 bullte. Brain-case oval in outline when viewed from above, a 

 little flattened posteriorly, the surface very smooth and evenly 

 inflated ; posterior portion unusually dis- 

 tinct from main j^art of brain-case, and 

 almost marked off by a constiiction at 

 front of interparietal ; in posterior view 

 the middle portion of brain-case rises 

 unusually high above interparietal, and 

 distance from lambdoid sutui'e to upper 

 margin of foramen magnum is unusunlly 

 reduced : paroccipital processes very short, 

 extending scarcely to level of lower lip 

 of foramen ; flooi- of brain-case with no 

 special features, the median I'idge and 

 lateral furrows well developed, the anterior 

 width of basioccipital less than median 

 length ; auditory bullsB rather large, evenly 

 inflated, without evident beak, the meatus relatively large, 

 without lip except along anterior border. Interorbital region 

 i-ather wide and short, smoothly I'ounded off at sifles though 

 tending to become slightly angular posteriorly in old individuals. 

 Zygoma slender and weak, the arch without special features, 

 the horizontal plate forming outer wall of anteorbital foramen 

 rather narrow, producing a very inconspicuous forward projection 

 on anterior boi'der of zygomatic I'oot wlien ^■iewed from abo^"e, its 

 own anterior border faintly concave and sloping obliquely forward 

 from above downward. Nasals not peculiar in general form, 

 their posterior border together with that of nasal branches of 

 premaxillaries deeply and irregularly lacinate,* not extending 

 noticeably behind lachrymal level. Incisive foramina relatively 

 larger than in Apodemug stjhmticus, their outer border nearly 

 parallel, the posterior border extending to level of anterior root 

 of m^, the anterior border separated from incisor by space equal to 

 greatest widtli of single foramen. Anterior portion of palate 

 * Not successfully represcutcd in fig. 170. 



Fig. 170. 



.MU-riimyx mhiulus. 



Nat. size. 



