Art. 24 TEXAN PLEISTOCENE VERTEBRATES HAY 13 



fig. 2; pi. 6, fi<2;. 1) to the new species. It ditfers from the type of 

 A. gratus in being hirger; in having the fourth crest more strongly 

 developed, the inner cone of the fourth crest being 80 mm. high in 

 place of the 62 mm. of A. gratus; in having a large talon approach- 

 ing a crest; and in having large tubercles at the inner ends of the 

 first and second valleys. The inner cone of the fourth crest has in 

 front a buttress which nearly blocks the third valley, and another 

 behind which joins closely the talon. This tooth diifers from the 

 upper last molar of A. oranus in some respects. The width does not 

 diminish from front to the rear, the width at the first crest being 

 9G mm. : at the fourth, 97 mm. There is no Avell-defined fifth crest, 

 but the talon may easily be regarded as a crest, and the 

 buttress of the fourth crest joins it closely. No other struc- 

 ture represents a talon. The Fort Worth tooth is only slightly worn, 

 but it is noted that trefoils begin to wear as in the teeth of the type 

 of A. orarius. The differences observed may be due to individual 

 variations or to those of closeh' related races. 



Dr. W. Freudenberg ^- described and illustrated a fine tooth which 

 he referred to Mastodon tropicus. This has remarkable resemblance 

 to the ui3per molar from Fort Worth. The height of the cones ap- 

 pears to be too great for M. tropicus. Freudenberg identified his 

 tooth as the lower left third molar. The slight obliquity of the 

 crests appears to confirm this disposition of it. He wrote that there 

 were incipient trefoils on the outer ends of the crests, but these 

 hardly reveal themselves in the figure. 



The upper third molar of the type of Aiiancus orarius differs in 

 various resj^ects from that of .1. gratus.^'^ A. orarius is a larger 

 and more rugged tooth, but that might be due to sex or some other 

 condition. It has five crests and a talon; the third valley is blocked 

 by butresses descending from the adjacent crests; there is a distinct 

 tendency toward the formation of butresses on the posttrite ends of 

 the crests; on the pretrite side there is, on the front half of the tooth 

 at least, a distinct cingulum, and this, nt the ends of the valleys, 

 expands into large tubercles. In Anancus gratus there are only four 

 crests and a hinder talon; the third valley is wide open; no but- 

 tresses are developed on the posttrite ends of the crests; there are 

 no traces of a cingulum on the sides of the tootli ; and no tubercles 

 are developed at the ends of the valleys. 



Aiiancus orarius differs in its lower hinder molar distinctly from 

 that of A. hrazozius.^^ The width is 0.45 of the length; the main 

 cones are wedge shaped and the valleys are wide; the buttresses are 

 simple and they do not block to a great height the valleys. In 



■=Ge<»l. Palaeont. Abhancll.. vol. 14, Heft. ;!. 



" Hay, Bull. Univ. Ti'xa.s, No. 71, 1917, p. 18, pis. 3, 4. 



" Hay, Pan. Amor. Geologist, vol. 29, 1928, p. 112, p). 8, fijjs. 1, 2. 



