CANIS 311 



lobe scarcely half as wide as inner ; on inner tooth the outer lobe 

 is nearly level with cutting edge, on second it lies slightly above 

 middle of crown, and on third slightly below middle of crown ; 

 posterior surface oblique, slightly concave, with noticeable longi- 

 tudinal furrow extending back from notch between lobes. Canines 

 large, usually 15 mm. or more in diameter at alveolus and about 

 twice as long, a size rarely if ever attained in domestic dogs, 

 their surface smooth except for a low antero-internal and 

 posterior-median logitudinal ridge, the upper teeth slightly longer 

 and less recurved than the lower. Premolars moderately spaced 

 except that pm 3 is nearly or quite in contact with the 

 carnassial ; first, second and third teeth essentially alike in the 

 two jaws, those of the mandible, however, slightly the less robust ; 

 first premolar both above and below single-rooted, the crown 

 simple, that of pm l subterete, that of pm 1 nearly twice as long as 

 broad, the height in both slightly less than length, the crown area 

 approximately the same as that of corresponding inner incisor, the 

 small cusp a little in front of middle and with slightly developed 

 anterior and posterior ridge. Second and third premolars two- 

 rooted, the crown about twice as long as wide, sub-elliptical in 

 outline, the inner margin sometimes (especially in pm 3 and pm 2 ) 

 slightly concave, the long axis nearly parallel with sagittal plane 

 except in pm 3 , which is obliquely set ; main cusp a little in front 

 of middle of crown, its height distinctly more than half length of 

 crown, its anterior and posterior cutting ridge well developed, the 

 posterior bearing a distinct secondary cusp situated over middle 

 of posterior root and relatively larger in lower than in upper 

 teeth ; a slight shelf-like projection behind secondary cusp ; pm i 

 similar to pm 3 but considerably larger, its secondary cusp 

 better developed and succeeded by a small but evident postero- 

 basal cusp springing from the posterior edge of crown ; cingulum 

 of all the smaller premolars complete though low and incon- 

 spicuous. Upper carnassial large and robust, the length of crown 

 along middle slightly more than twice greatest breadth exclusive 

 of antero-internal lobe, the main axis of the tooth extending 

 evidently through middle of crown, so that the small, cuspless 

 inner lobe stands as an offset, slightly breaking the symmetry of 

 the outline ; main cusp slightly behind middle of crown, its 

 height more than half length of tooth, its axis slanting distinctly 

 backward, its anterior and outer surfaces evenly convex except 

 for the rudimentary longitudinal ridge on basal two-thirds of 

 front, its inner surface, together with that of posterior cusp, 

 flattened ; posterior cusp low and robust, obscured by its very 

 high nearly horizontal commissure which meets the somewhat 

 shorter but equally trenchant commissure of main cusp at an 

 angle of about 75° ; cingulum complete, though low and incon- 

 spicuous. Lower carnassial narrower than upper but with equally 

 high crown, the most elevated portion in front of middle instead 

 of behind it ; protoconid large and robust, resembling main cusp 



