316 PROCEEDINGS OF THE ACADEMY OF [1892. 



PROTOPSALIS Cope.i 

 Syn. ? Li?unofeiis^ Marsh. 



The name Limnofelis is of older date than Protqpsalis, but was 

 founded upon such imperfect specimens that no generic characters 

 can be derived from them. The probability that both name^ refer 

 to the same thing is given by the fact that both are very large 

 animals, referable to the Hycenodontidce and occurring in the 

 Bridger beds. 



The number of teeth in this genus is not known ; an anterior lower 

 molar (mi ?) resembles that of Oxycena, having a nietaconid and 

 fairly large basin-shaped heel; m- ? however, is strikingly like the 

 inferior sectorial of the cats, except for the greater height and nar- 

 rowness of the protoconid ; the metaconid has disappeared and the 

 talon is a minute rudiment. The skeleton, so far as it is known, 

 closely resembles that of Oxycena, but the bones are much larger, 

 more massive and with more prominent processes for muscular 

 attachment. The cuboid is very peculiar ; the calcaneal surface is 

 even larger and more oblique than in Oxyccna and is slightly con- 

 vex, while the astragalar facet, which in the Wasatch genus is nearly 

 plane, is in Protopsalis deciiledly concave from before backward. 

 The metapodials are relatively stouter than in Oxycena. 



One species : P. tigrinus Cope (Syn. ? Limnofelis Jerox Marsh). 

 Bridger. 



HEMIPSAL0D0N3 Cope. 



This, the largest of known creodonts, is nearly allied to Pterodon, 

 but distinguishable from it by the character of ni^, which in the 

 latter has a rudimentary trenchant heel, but in the former the talon 

 is larger and basin-shaped, with continuous margin, as in Oxycena ; 

 the metaconid is probably absent. This is the only molar the con- 

 struction of which is known, but the number of teeth in the mandible 

 is known to be : I3 Ct P? M3. The canine is exceedingly power- 

 ful and the jaw very mas.-ive ; the chin is deep and abruptly rounded 

 and the symphysis very long, extending to p*. The femur is very 

 like that of Protopsalis, but has a much longer neck and small 

 hemispherical head ; the second and third trochanters are not very 

 prominent and the latter is 2)laced low down on the shaft ; the 



1 Amt-r Naturalist. 1880, p 745. 



2 Am. Joitrn. Sci. and Arts, 3rrl Ser., Vol. IV, 1872, p. 202. 

 ' Amer. Naturalist, 1885, p. lt)3. 



