90 E. II. Barbour — New longirostral Mastodon, 



(l,322 mm ). Three large fragments of the tip, found at the end 

 of the mandible, when set in position, increase the length to 

 about 56 inches (l,424 mm ). Its total restored length, including 

 the tusks, is 69 inches (l,754 mm ). There is every probability 

 that the length could not have been less than two full meters. 

 Dr. Lull is undoubtedly right in believing that the tusks, as 

 restored, are too short. We fully agree that they may have 

 been two or three times as long as shown in the accompanying 

 figures. In any event, the length of the tusks must be assumed. 

 Accordingly a very moderate size was chosen. The great size 

 and strength of the ascending ramus, and especially the large 

 roughened coronoids, suggest longer tasks. It is much larger 

 than either of the Tetrabelodons, longirostris or angustide?is, 

 and is of different proportions. In the best known specimen 

 of Tetrabelodon angustidens the mandible is about 46 inches 

 (1 ,169 mm ) long, or with tusks included, about 52 inches (l,322 mm ). 

 In Tetrabelodon longirostris, the symphys is is not greatly pro- 

 duced, and the inferior tusks are relatively large. 



Tetrabelodon campester is much smaller, the symphysial 

 prolongation is much shorter, the ramus thin, and the inferior 

 border curves without angle into the ascending ramus. 



The rostrum of this new mastodon is greatly elongated and 

 noticeably decurved. The rami diverge by curves the con- 

 vexity of which is outward ; while in angustidens it is inward. 

 The lingual groove is 2 inches (51 mm ) deep, and 3 inches (T6 mm ) 

 broad, growing shallower toward the tip, and is bounded on 

 the sides by narrow rounded edges. The long attenuated sym- 

 physis is ancestral, and its maximum development seems to 

 have been reached in this species. The narrowed and reduced 

 alveolus seemingly mark's a decline in the mandibular tusks, 

 and consequent to their reduction and loss, follows the reduc- 

 tion and final suppression of the prolonged rostrum. 



The ramus is massive and powerful, being 31 inches (788 mm ) 

 from the bifurcation to the condyle, by 8 inches (203 mm ) deep, 

 and 4 inches (102 mm ) thick at the molars. Immediately back 

 of the molars the thickness increases to 5 inches (12T mm ). The 

 symphysial prolongation is 28-J- inches (724 mtn ). It is 5 inches 

 (127 mm ) deep at the entrance of the mental foramen, by 4 inches 

 (102 mm ) wide. This makes a very narrow rostrum. Tetrabe- 

 lodon angustidens, measured at the same point, is about 4 

 inches (102 mm ) deep, by 5 inches (12T mm ) wide. The inferior 

 mandibular border is thick and round under the molar, but 

 narrows rapidly toward the angle. The angle is thin and pro- 

 nounced, and flares outward very unlike modern and fossil 

 elephants. 



The ascending ramus is very broad and erect, and rises well 

 above the level of the molars, but not as high as in Tetrabelodon 



