CRANIA FROM THE MOUNDS OF FLORIDA. 



441 



of which the cingule of the canine becomes the cusp (2. e. the palatal cusp) of the 

 premolar ; that should a new cingule be developed from the premolar it becomes in 

 the molar the third cusp ; and that should the molar possess 

 more than four tubercles, three of these will be cusps, the 

 remainder will be cingules. The simplest expression of a cone 

 is exhibited in the incisors and canines, which may be said to be 

 the lowest of the series, and that the highest expression any- 

 where seen is in the lower teeth. 



In figure 27 the beginning of the 

 bicuspidate form of tooth is seen in the 

 manner by which the cingules are seen 

 to vary. 



In figure 28 the basal cingules while 

 not so concrete are yet sufficiently well- 

 developed to retain distinctive names and are of the nature 



of unusual variations in form in transition between the incisorial and the caniiii- 

 form shapes of monocuspidate teeth and those of the bicuspidate type. The canine 

 tooth exhibits on either side of the centre of the tooth a narrow depression or valley. 

 The folds of enamel at the side of the depressions just named are of importance 

 in describing the variations of the bicuspids. In this paper these folds will receive 

 the name of commissures. Figure 29 shows, in a conspicuous way, the distinctness 

 of these folds. 



Fig. 27, a. lateral maxil- 

 lary incisor; b. c. su- 

 pernumerary teeth, 

 probably maxillary 

 incisors exhibiting 

 the beginniug of an 

 additional cusp at 

 the base of the pala- 

 tal aspect of the 

 crown. 



Fig. 28. — Two maxilliary in- 

 cisors and one canine ex- 

 hibiting well-developed 

 cingules. 



Fig. 29. — The premolars and molars of the 

 lower jaw (1,827 Morton Collection.) The 

 first premolar, fig. 29, retains depression 

 on either side of the basal convexity. 



. 30. — The folds of the upper premolar are 

 shown. The first tooth is actually larger 

 than the second and exhibits a large fold on 

 the posterior surface of the crown, back of 

 the posterior enamel fold. 



In the molar series the succession of cusps from the monocuspidate to the poly- 

 cuspidate is clearly shown. It is necessary here to distinguish between the forms 

 of the upper and lower molars. The lower molars resemble the lower premolars in 



Fig. 31. — The lower teeth showing the 

 simple form of the second molar as 

 compared with the first and third. 



Fig. 32.— The first and 

 second upper molars. 



Fig. 33. — The third upper 

 molar showing ellipti- 

 cal form of crown. 



the disposition for the folds of enamel on the anterior and posterior parts of the 

 tooth to thicken. The second molar shows this tendency to a less degree than 

 either the first or the third, and the posterior fold to a greater degree than the 

 anterior. The posterior fold is apt to bear a distinct cusp developed in the middle 

 of the posterior commissure. 



