14 PROCEEDINGS OF THE NATIONAL, MUSEUM Vol. 68 



Anancus hrasozius the width is only 0.40 of the length of the 

 tooth; the main cones are high and columnar; the valleys are nar- 

 row ; the buttresses are more complicated ; and they block the valleys 

 to a relatively great height. 



The left lower third molar of the type specimen of this species 

 was presented by Doctor Francis to the United States National 

 Museum, and it now has the catalogue number 11,377. 



ANANCUS DEFLOCCATUS, new species 



Plate 7; plate 8, fig. 1 



The second mastodon found near Sinton is represented by the 

 left horizontal ramus and parts of its second and third molars, and 

 by the hinder half of the lower right third molar. The individual 

 was one of rather advanced age, as the hinder teeth are worn on all 

 the crests. 



Name from Latin defloocaius, a worn out, rusty old fellow (Ains- 

 worth's Dictionary). 



The horizontal ramus (pi. 8, fig. 1) is quite different from that of 

 Anancus orarms, being much lower in front, 150 mm. or less at the 

 front of the second molar, instead of 200 mm. as in A. orarius. 

 Below this point the thickness is 105 mm. At the rear of the third 

 molar the height is 130 mm., the width 180 mm. The symphyseal 

 articulation is 135 mm. long and 96 mm. high. The jaw seems not 

 to have ended in a beak as in many mastodons. There are three 

 mental foramina, all opening near the alveolar border. A small one 

 is situated below the hinder border of the front root of the second 

 molar, another just below the front border, and a third about 

 35 mm. further forward. The second and the third have a diameter 

 of about 5 mm. 



In the jaw are remains of the second and the third molars. Of 

 the second there remain the anterior root and the hinder root, capped 

 by a part of the last crest worn down so that only the dentine is 

 seen and a fragment of the enamel on the inner border. More of 

 the tooth was present but was lost in collecting. The front root is 

 about 50 mm. wide and 40 mm. front to rear. It seems a large rem- 

 nant for a tooth so nearly worn out. From the front of this root 

 to the rear of the tooth is 110 mm. The width of the crown in front 

 may have been more than 70 mm. ; at the rear, nearly 100 mm. The 

 fore-and-aft width of the last crest was at least 36 mm. There could 

 therefore have been only three crests. The structure of these can 

 be judged only from their condition in the hindmost molar. Un- 

 fortunately the third molar is much injured, a large section of the 

 middle of its length being absent (pi. 7). The crown was 230 mm. 

 long, and it consisted of five crests and a hinder talon. Width of 



