RHINOLOPHUS 



141 



bottom of palatal emargination posteriorly, but otherwise free; 

 rostral inflation evident but low, its posterior border running 

 gradually into that of interorbital region, its anterior margin 

 over middle of anterior molar ; maxillary triangular in outline 

 when viewed from the side, the heavy canine projecting forward 

 and downward from its anterior apex ; anteorbital foramen small, 

 over middle of second molar and directly beneath minute 

 lachrymal foramen, the plate forming outer wall of canal 

 thread-like, occasionally absent. 



Teeth. — Except for the minute premolars and upper incisors the 

 teeth are robust and heavy relatively to size of skull. Upper 

 incisor minute, low, the crown subterete, wider than root, lower 

 externally than internally, each tooth placed near middle of 

 oblique anterior border of premaxillary, the space between the 

 two nearly double diameter of crown. Lower incisors strongly 

 imbricated, forming a short, very convex row between canines, 

 their crowns longer than high, compressed (the outer tooth less 

 than the inner), deeply and equally trifid. Upper canine very 

 large, and noticeably the highest tooth in the maxillary series, 

 the root oblique, the shaft abruptly bent downward at level of 

 well developed cingulum, its length along cingulum about three- 

 fourths height ; cross section of shaft triangular, the inner surface 

 flattened, slightly concave near cingulum, the posterior edge 

 trenchant, the anterior edge narrowly sub-trenchant, the outer 

 surface with well developed median longitudinal ridge and 

 noticeable posterior concavity. Lower canine not so large as 

 upper, the flattened surface of its shaft directed posteriorly to 

 oppose front of upper canine in mastication. Anterior upper 

 premolar minute, resembling upper incisor in both size and form, 

 entirely external to tooth-row, occasionally absent. Posterior 

 upper premolar large, closely crowded against canine, its crown 

 area about equal to that of second molar, without secondary 

 cusps, its main cusp intermediate in height between canine and 

 metacone of first molar ; posterior border of crown slightly but 

 evidently emarginate. Anterior lower premolar less than half as 

 high as posterior premolar and with barely half its crown area, 

 the two teeth crowded closely together between canine and first 

 molar ; shaft of anterior tooth with slightly developed concave 

 area on inner side, that of posterior tooth with better defined 

 posterior concavity, its inner side convex ; middle lower premolar 

 resembling anterior upper premolar, its position equally external 

 to tooth-row. Upper molar with large though not unusually high 

 protocone, behind which in m 1 and m 2 there is a low-lying 

 heel (best developed in m 1 ), but no indication of a true hypocone ; 

 paracone and metacone well developed, the latter slightly the 

 higher in m 1 and m 2 , this reversed in m 3 ; styles and commis- 

 sures in m 1 and m 2 well developed, forming a normal VV-pattern ; 

 in m 3 the metastyle and fourth commissure are absent, and the 

 third commissure is much reduced in length ; crown area of m 3 



