842 EODENTIA 



Skull. — The .skuU ditVers conspicuously tVoiii tliui of ;ill otlior 

 l*iUi'opeau Murimti in the striking (-ontrast between the short 

 weak rostrum and the hirge, much elongated brain-ease ; 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 profile 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 

 anteriorly than posteriorly, to interparietal, where a slight 

 break in the profile is produced by the more abrupt convexity 

 of the overhanging posterior portion of brain-case ; ventral 

 profile without special features, essentially straight from incisor 

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

 bulla:;. 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 part of brain-case, and 

 almost marked off by a constriction at 

 ^TN^^^ front of interparietal ; in posterior view 



^^__^ the middle portion of brain-case rises 



unusually high above interparietal, and 

 distance from lambdoid suture to upper 

 margin of foramen magnum is unusually 

 reduced ; paroccij)ital processes very short, 

 extending scarcely to level of lower lip 

 of foramen ; floor of brain-case with no 

 special features, the median ridge and 

 Via. 170. lateral furrows well developed, the anterior 



Micromys minuUis. •ij_t o ^ • • -i ^ t n ^• 



Nat. size. Width 01 basioccipital less than median 



length ; auditory bullae rather large, evenly 

 inflated, without evident beak, the meatus relatively large, 

 without lip except along anterior border. Interorbital region 

 rather wide and short, smoothly rounded off at sides though 

 tending to become slightly angular posteriorly in old indiAdduals. 

 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 border of zygomatic root when viewed from above, 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 Apodemus sylvaticus, 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 width of single foramen. Anterior portion of palate 

 * Not successfully represented in fig. 170. 



