442 



CRANIA FROM THE MOUNDS OF FLORIDA. 



In the upper jaw the cusps are not so symmetrically arranged as in the lower, 

 nor are the commissures so conspicuous. 



In figure 32 the parts are typically disposed. The fifth cusp in the second 

 molar is not an outgrowth of a commissure as in the lower jaw, but is a basal 

 cingule of the Irypocone. The axis of the upper molar is disposed to be oblique. 

 The contact of the protocone and the mesocone forms an oblique line which has long 

 been noted. The greater length of the crown surface in the direction of the paracone 

 and the hypocone has escaped notice. It is marked in both of the teeth in figure 32. 



The obliquity in the tooth shown in figure 33 is marked. 



3 4 5 



Fig. 34. — Seven examples of variations of tbe upper molars. 



1. (No. 140). The elements of the Irypocone are duplicated and appear as part 

 of an enamel fold (which is not commissural) on the posterior surface of the crown. 

 A similar arrangement is seen in figure 30, upper premolar. — 2. (No. 828). Two 

 elements of the value of cingules are here present. The first of these is the hypo- 

 cone ; the second lies directly to the palatal aspect of the protocone. — 3. (No. 1,488). 

 In the second molar the cingules are three in number and clasp the posterior and 

 palatal aspects of the crown, throwing in the paracone from the periphery. — 4. 

 (No. 828). The second molar exhibits two cingules, one the h} r pocone in its usual 

 position, the other placed directly back of the paracone. — 5. (No. 29). The first 

 molar showing an exceptional prominence of the enamel fold on the buccal aspect. 

 — 6. (No. 1,467). The presence of the enamel folds on either side of the protocone 

 and paracone is evident. In the valleys thus formed are seen two well-defined 

 eminences which do not receive names. — 7. (No. 760). A conspicuous nodule, 

 apparently anomalous, is seen on the buccal aspect of the first molar.— The anterior 



Fig. 35.-The third upper molar exhibit- 

 ing a disposition of the parts to 

 assume a tricuspidate form. 



Fig. 36.-The parts not obliquely dis- 

 posed and as a result the proto- 

 cone and mesocone scarcely 

 touch and do not form an ob- 

 lique ridge. 



Fig. 37.— The third lower molar. The 

 cusps are broken up into small 

 folds. Each cusp represent three 

 such folds and the entire tooth 

 is much higher on the borders 

 of the grinding surface than in 

 the centre. 



commissure of the deciduous molars marked in the lower jaw extends forward to a 

 degree greater than is the case in the upper ; two examples are illustrated in the 

 above series. The anterior commissure of the first molar of No. 4 is produced and 

 forms a cone-like figure whose base is directed backward. Such a configuration is 

 seen in the last of the series of premolars in some mammals with long slender 

 jaws. It 'denotes absence of pressure on the anterior part of the tooth and a 

 resultant disposition in the tooth to advance in such direction. 



