10 PROCEEDINGS OF THE NATIONAL MUSEUM Vol. fi8 



The inner ends of the first and second valleys were occupied by 

 large elongated tubercles. A 2:)ressure area is present on the front 

 end of the crown ; the talon on the hinder end was almost obliterated 

 by the pressure of the molar behind. The crown is 122 mm. long 

 and 93 mm. wide at the first and third crests. This tooth probably 

 belonged to the type specimen. 



The upper right third molar in its fragment of the maxilla is 

 practicall}' complete (pi. 3, fig. 1; pi. 4, fig. 1; pi. 5, fig.l). How- 

 ever, the inner half of the pretrite portion of the third cone was lost 

 in collecting the tooth and the distal ends of the hinder portion of 

 the rear root are broken off. The grinding face is worn as far back 

 as the fourth crest. The length of the crown is 202 mm., measured 

 on the midline. The width at the first crest is 102 mm.; at the 

 second, 105 mm.; at the third, 100 mm.; at the fourth, 90 mm.; 

 at the fifth, 68 mm. At the rear is a small talon of 3 tubercles. 

 The outer cones of the crests are wedge shaped, and the enamel 

 figures resulting from wear are elongated in the direction of the 

 crest. As shown on the third and fourth crests, each outer cone 

 terminates in 4 conules. On the hinder face of the first outer cone 

 near the midline, is an area of dentine on the point of being con- 

 nected with the dentine of the main area of wear. A large, worn- 

 down tubercle in the valley at the midline presents another area of 

 dentine. Near the midline, at the base of the hinder face of the sec- 

 ond outer cone, is a similar area of dentine. These remains of but- 

 tresses would each in time have had its dentine area joined to that of 

 the principal cone. On the inner half of the first, second, and third 

 crests are well-developed trefoils. On the hinder face of the fourth 

 crest the buttress is wanting. The basal lobes of the trefoils are 

 pointed. This appears to have been produced by a chopping motion 

 between the jaws instead of a sliding one. On such manner of 

 wear Schlesinger ® has based his subspecies of Mastodon angustidens 

 suhtapiroideus. 



The original height of the outer cones of the first and second 

 crests can not be determined exactly. Measured from the lower 

 border of the enamel the heights are 53 mm., 61 mm., 68 mm., 68 

 mm., 45 mm. The third cone was originally but little higher than 

 now. The inner cone of the fifth crest is 66 mm. high. The enamel 

 of the trefoils is thick and moderately folded. 



The roots of this tooth, except the outer anterior one, are shown 

 on the inner side of the fragment of maxilla (pi. 4, fig. 1). The 

 anterior branch of the inner front root rises to a height of 150 mm., 

 the posterior branch to a height of 125 mm., and the front part of 

 the great hinder root to a height of 125 mm. 



« Denkschr. naturh. Staatsmus., vol. 1, 1921, p. 36 . 



