MARTES 371 



or slightly concavo-convex, the concavity, when present, on outer 

 side ; cusp simple, its height a little less than length of crown 

 along base, its posterior surface with slightly developed longi- 

 tudinal ridge. Crown of pm? somewhat longer than that of pm 2 , 

 but its area much greater owing to widening of strongly convex 

 inner side ; cusp essentially as in pm 2 though somewhat higher. 

 Second lower premolar about equal in size to pm 2 , but axis of 

 shaft more anterior in position ; pm 3 essentially like pm 2 , but 

 cusp with faintly indicated anterior longitudinal ridge, and 

 posterior ridge with a slight nodule or rudimentary basal cusp 

 (sometimes absent) ; pm i noticeably larger than pm 3 and with a 

 well developed secondary cusp at middle of posterior border of 

 main cusp. Upper carnassial (pin 4 ) long and narrow, the width 

 of crown just behind internal lobe less than half length along 

 outer border, the internal lobe robust, its diameter in line of 

 tooth-row nearly or quite equal to width of trenchant portion of 

 crown, its axis nearly perpendicular to main axis of tooth, its cusp 

 well developed, about as high as that of pm 1 , and separated from 

 main cusp by deep concavity ; main cusp robust, its height 

 contained about 1| times in length of crown, its axis slanting 

 a little backward, its anterior border with well developed 

 longitudinal ridge ; posterior cusp about half as high as main 

 cusp, its outer surface sloping obliquely to well developed 

 cingulum, the two cusps connected by a high, sharply trenchant 

 and obtusely angled commissure. Lower carnassial with crown 

 nearly 2| times as long as broad, the sectorial portion of the 

 tooth consisting of a much distorted triangle, the paraconid 

 forming anterior extremity of tooth, its anterior border nearly 

 perpendicular, its posterior commissure meeting anterior commis- 

 sure of the higher protoconid at an abrupt angle, the two together 

 acting in opposition to the angled commissure of upper carnassial ; 

 metaconid reduced to a subterete posterointernal process on 

 base of protoconid, its area scarcely one-sixth that of larger 

 cusp ; crushing portion of crown slightly broader than trenchant 

 portion, its outline sub-circular with slightly raised edge, this 

 edge forming a noticeable though low postero-external cusp 

 separated from base of protoconid by a shallow but distinctly 

 angled notch. Second lower molar about equal to heel of 

 carnassial in size and essentially like it in form, the crown flat, 

 with faintly indicated outer ridge and low postero-internal cusp. 

 Upper molar large, its crown area at least equal to that of 

 carnassial, its greatest diameter about equal to outer length 

 of carnassial (see measurements, p. 378), the diameter of inner 

 portion of crown usually much greater than that of outer 

 portion, the median constriction well marked ; outer portion of 

 crown with two small cusps, probably the paraoone and metacone, 

 the latter more than half as large as former, the outer margin of 

 tooth often though not invariably notched between them ; inner 

 portion of crown with a. slightly curved, ridge-like antero- 



2 b 2 



