APODEMUS 801 



i-()\v iiuR'li ];irt((^i' than those of the ijinci- and outer rows, tlie 

 tubercles of the dili'erent rows partly joined by cross-ridges, ajid so 

 disposed as to form three transverse laminae having somewhat the 

 form of forwardly-bowed crescents. In each tooth this complete 

 pattern is only approximated ; in m'^ it is imperfect posteriorly, 

 in m'^ both anteriorly and posteriorly, while in m^ it is scarcely 

 more than recognizable. For convenience of description the 

 tubercles representing the complete pattern may be numbered 

 transversely 1 to 9, beginning with the first on inner side and 

 ending with the third on outer side ; those of the inner row 

 will therefore be 1, 4 and 7, those of the middle row 2, 5 and 8, 

 those of the outer row 3, 6 and 9. Crown of m^ more than one 

 and a half times as long as broad, its length nearly and area 

 fully equal to that of two succeeding teeth combined ; tubercles 

 of outer row slightly larger than those of inner ; anterior 

 crescent slightly distorted by the small size oi tl and the very 

 broad, shallow angle between its inner border and the outer 

 border oi. t2 ; a small but evident projecting supplemental loop 

 usually present in angle between to and t2, a similar but less 

 developed loop occasionally present in that between t2 and tl ; 

 second crescent essentially similar to first, and partly oi- com- 

 pletely joined to it by a narrow ridge extending between tS and 

 the outer base of t5 and occasionally a similar ridge between tl 

 and the outer base of to, the ridges variable in development 

 though rather constant in position ; third crescent much distorted 

 by the pushing forward of i9 and tl so that the three cusps of 

 this lamina lie in the same transverse line, and the re-entrant 

 angles separating them from t6 and ti respectively are much 

 narrower than those behind iirst lamina ; t9 is broadly connected 

 with tQ anteriorly, so that the two might almost be interpreted 

 as parts of a deeply divided t6 ; t7 is similarl}^ connected with 

 ti, and, though well developed, is the most reduced cusp in the 

 tooth ; postero-external border of crown usually with a faintly 

 indicated supplemental loop, this never so well developed as in 

 Ajwdemus epimelas. Second upper molar sub-circular in outline, 

 its first lamina incomplete by the absence of V2 ; i3 very small, 

 terete ; second and third lamintB essentially as in m^ ; postero- 

 external loop excessively minute, though usually present in unworn 

 teeth. Third upper molar similar to m? in form but scarcely half 

 as large. In moderately worn condition it usually has the appear- 

 ance of a sub-circular tooth with two re-entrant angles on inner 

 side extending about half way across crown and occasionally a 

 slight notch on outer side near middle ; when unworn it is 

 possible to identify tubercles 1, 4, 5 and 8, the inner re-entrant 

 angles corresponding to the spaces between first and second and 

 second and third lamina;, the notch on outer surface to the 

 re-entrant angle at front of th. Lower molars consisting of a 

 series of paired, equal, nearly distinct tubercles, each tooth 

 terminating posteriorly in a single median tubercle usually much 



3 F 



