16 PROCEEDINGS OF THE NATIONAL MUSEUM Voi. «!Jv 



to be a third premolar (pi. 3, iigs. 2, 8). To which of the two 

 species of mastodons found by Doctor Francis it belonged, if either, 

 it is impossible to determine. The tooth had not yet come into 

 action. It appears to be an upper tooth, but whether upper or 

 lower, it belonged to the left side. The length of the crown is 

 31 mm.; the greatest width, that at the second crest, is 30 mm.; 

 the heighth, 22 mm. Seen from above the crown is approximately 

 triangular, with the angles rounded. The anterior crest consists 

 of a pretrite cone without subsidiary conules. The posttrite half 

 consists of a principal cone against whose hinder face is a conule, 

 the summit of which is free. The conule forms a sort of buttress. 

 The hinder crest presents, in the pretrite half, a main cone between 

 which and the medium cleft is a subsidiary conule. The front face 

 of the main cone shows a rather prominent buttresslike ridge which 

 partly blocks the valle3^ The rear face presents another ridge not 

 so large but more distinctly marked off from the main cone. These 

 buttresses appear to presage the development of a trefoil on the 

 second crest. The posttrite half of the second crest consists of a 

 'arge principal cone and a row of three conules between it and the 

 midline. The main cone is furnished on its front face with a dis- 

 tinct ridge descending to the valley, and a similar one on the rear 

 face. 



Above the base of the crown in front is a prominent beaded cingu- 

 lum, and this passes backward on the pretrite side to the mouth 

 of the valley. It is not present on the posttrite side. At the rear 

 of the crown is a cingulum of a row of about 20 small tubercles 

 of varying size. At a little higher level and between the cingulum 

 and the base of the second crest is a row of about 8 conules which 

 appear to represent a rear talon. The surface of the enamel is 

 everywhere wrinkled, and there is shown a tendency to the forma- 

 tion of ridges and sharp pustules. 



