NO. I LOWER EOCENE MAMMALIAN FAUNAS — GAZIN 37 



of the paraconid and metaconid, gives the trigonid a somewhat less 

 triangular appearance than in T. tenuicuhis. 



Were it not for the more noticeable upward convergence of the in- 

 ner and outer walls of the lower molars, T. pearcei might well have 

 been referred to Anemorhysis. A. suhlettensis, a slightly smaller form, 

 otherwise shows a shorter and broader trigonid and a relatively 

 longer talonid. Anteroposterior development of the talonid also char- 

 acterizes P4 in A. suhlettensis. M3 in Anemorhysis muscula is very 

 close in size to this tooth in T. pearcei (U.S.N.M. Nos. 22382 and 

 22799), and although M3 is not known in A. suhlettensis, the antero- 

 posteriorly shorter trigonid and slightly more erect outer wall of the 

 protoconid strongly suggest that A. muscula is more properly re- 

 ferred to Anemorhysis than to Tetonoides. I strongly suspect that 

 Tetonoides is close to the line of development for Anemorhysis. 



MEASUREMENTS IN MILLIMETERS OF LOWER TEETH OF 



Tetonoides pearcei and Tetonoides tenuicuhis 



T. pearcei T. tenuiculus 



Y.P.M. U.S.N.M. U.S.N.M. A.M. U.S.N.M. 

 No. No. No. No. No. 

 14084 22382 22383 15066 19154 



P2-P4 (at alveoli) 2.8 2.7 



Mi-Ms, inclusive 54 



Ps, anteroposterior diameter: 



transverse diameter 1.3:1.0 



P4, anteroposterior diameter : 



transverse diameter 1.5:1.3 1.5:1.4 



Ml, anteroposterior diameter : 



transverse diameter 1.8:1.5 1.8:1.6 



M2, anteroposterior diameter : 



transverse diameter 1.7:1.6 1.8:1.6 1.8:1.7 1.7:1.6 



Ma, anteroposterior diameter : 



transverse diameter 2.2 : 1.4 2.1 : 1.3 



ABSAROKIUS, near A. ABBOTTI (Loomis) 



(Plate 5, figure 3) 

 A lower jaw from the Red Desert area, that McGrew assures me 

 is from the Gray Bull level, is found to represent Ahsarokius rather 

 than Tetonius. The specimen (U. of Wyo. No. 1644, see pi. 5, 

 fig. 3), collected by Henry W. Roehler in SW^NE:! sec. 10, T. 24 N., 

 R. 100 W., includes P3-M3 and exhibits all the alveoli anterior to P3. 

 The molar teeth are relatively small but can be matched in a particu- 

 larly small specimen of A. ahhotti (A.M. No. 14672) from the Lysite, 

 but P4 in the Red Desert specimen is a little larger. The relatively 



