167 



705. The right minus of the lower jaw of an Alligator, from which the |x>stenor 

 part of the inner alveolar wall has been removed, showing the five posterior 

 teeth lodged in a common alveolar groove, the germs of the successionol teeth, 

 and the effects of their pressure upon the bases of time in place. Here like- 

 wise may be observed the short obtuse crowns of the' posterior teeth in tin 

 Alligator, and the constriction or cervix which separates the crown from thu 

 fang. I'urrhfued. 



760. The left nun us of the lower jaw of an Alligator, from which a section of tin- 

 outer alveolar wall has been removed, exposing three complete sockets with 

 the germinal recess at the inner part of their base, where the matrix of the 

 succeasional teeth was lodged : it also exposes four teeth i* '/*, on removing 

 which the germs of their successors may be seen occupying the germinal re- 

 <.<-. 'I'll. ;ilorl>.-nt |>I.MI-> i v it, ,| liy that "t'tlir posterior tooth has pro- 

 duced a circular excavation on the inner side of its base. Purchased. 



767. The fourth tooth of the lower jaw, or canine, of an Alligator (Alligator 



The crown it ihort and conical, with two opposite ridge* nearer the concave tide ; the in- 

 termediate tract* of enamel present numerous feeble longitudinal rtrur and a minutely reticu- 

 lar surface : an almost circular piece hat been removed by progressive absorption from thr 

 inner ride of the hue. 



Purchased. 



768. Several teeth of an Alligator (Alligator nyer), in different stages of growth and 



deny. 



One show* the apex of a succession*] tooth projecting through the pulp-cavity, whkh has 

 been exposed by the breaking away of the crown : in another the almost perfectly formed 

 tooth is surrounded by the remains of its predecessor, reduced to a mere irregular shell of 

 dentine. 



Purcktued. 



