838 



edge narrow aiul Hbriipi in adults, lower in innnatuie indi\ iduals, 

 a faint but evident trace visible in sucklings ; posteriorly the 

 bead is continued along side of upper surface of brain-case as a 

 slight ridge to lambdal suture, which it meets about 2 mm. 

 beyond termination of interparietal. Anteorbital foramen some- 

 what more widely open than in A. sijlvatlcus. Incisive foramina 

 noticeably shoi'ter and (relatively) Avider than in the other 

 European members of the genus, the posterior margin extending 

 barely or not ta level of alveolus of m\ the anterior margin 

 separated from alveolus of incisor by a distance fully equal to 

 combined width of foramina. Auditory bullae more inflated than 

 in Apodemus syJvaticus, so that hamular is nearly or quite in 

 contact with inflated portion instead of with a contracted beak- 

 like process as in the related species. While in general 

 resembling that of Apodemus sylvaticus the mandible is readily 

 distinguishable by the narrower less curved angular process and 

 the higher more curved coronoid, the extremity of wdiich is 

 distinctly above level of condyle. 



Teeth. — The teeth are noticeably smaller than in Apodemus 

 sylvaticus : alveolar breadth of m^ scarcely more than one-third 

 greatest width of palate between tooth-rows, the narrowness 

 chiefly due to the relatively small size of the tubercles of the 



outer row. Crown of w} slightly 

 longer than that of m^ and m-^ 

 together, its area decidedly more 

 than that of the two other teeth 

 combined. Crescents less curved 

 than in A. sylvaticus, and showing 

 less tendency to become joined by 

 connecting ridges. First upper molar 

 with t3 reduced to a mere appendage 

 to the outer border of f2 ; tl well 

 developed, distinct, very posterior in 

 position, this peculiarity together with 

 the small size of t3 producing great 

 distortion of the anterior crescent ; 

 no supplemental loops in angles 

 between ^3 and t'2 or t2 and ^1. 

 as in A. sylvaticus except for the 

 flattening of the second crescent and the more abrupt rounding 

 of the posterior border resulting from the complete absence of 

 all trace of t9. Second upper molar with no trace of ^3 and 

 with re-entrant angle on outer surface of <6 so reduced that the 

 tubercle is often practically entire. Third upper molar as in 

 A. sylvaticus but with its elements even more indistinct, and tQ 

 practically absent, the outer border of tooth consequently entire. 

 Maxillary teeth essentially as in A. sylvaticus, but paired 

 tubercles less distinct from each other and outer ledge with its 

 rudimentary cusps in m^ and j/(.j nearly obsolete. 



¥lG. KiO. 



Apodcinas agrarius. 

 X 10. 



Clieek-teetli. 



Rest of tooth essentially 



