NEW PALEOCElSrE MAMMALS SIMPSON 



243 



LITOMYLUS," new genus 



Type. — Liiomylus dissentaneus, new species. 



Distribution. — Middle Paleocene, Fort Union, Mont. 



Diagnosis. — Lower teeth generally similar to Protoselene but rela- 

 tively narrower and more lightly built. P4 with sharp anterior blade, 

 rudimentary anterior cuspule low on the crown, low well-defined 

 metaconid separated from protoconid by a distinct pocket, talonid 

 relatively shorter and lower than in Protoselene. Talonid of M3 less 

 elongate. Molar paraconids vestigial and median as in Protoselene; 

 unlike Ellipsodon or Litalefes. 



LITOMYLUS DISSENTANEUS,S2 new species 



Type.— U.S. 'N.M. no. 9425, left lower jaw with P3-M3. Collected 

 by A. C. Silberling. 



Horizon and locality. — Gidley Quarry, Fort Union, Middle Paleo- 

 cene horizon. Crazy Mountain Field, Mont. 



Diagnosis. — Sole known species of genus. Measurements of type 

 in millimeters: 



HAPLALETES,53 new genus 



Type. — Haplaletes disceptatrix, new species. 



Distribution. — Middle Paleocene, Fort Union, Mont. 



Diagnosis. — P3 with small basal paraconid and rudimentary meta- 

 conid. (P4 unknown.) Protocone distinct on P^ and large on P*. 

 Kudimentary metacone on paracone slope of P*. Mi_2 and particu- 



" Alrdi, simple +Ai6Xos, millstone. From the simple molars and in analogy with Haplomylus, Litaletes, 

 and others. 



** Dissentaneus, disagreeing. From its disagreement with the more common mioclaenines. 



" 'A3rX6os, simple +(iX€r>;s, grinder. From the single molars and in analogy with Haplomylus, Litaletes, 

 and others. 



