FOKT UNIOX OF CRAZY MOUNTAIN FIELD, MONT. 175 



single mode. These premolar characters are certainly not generic 

 and probably not good specific characters. 



3. "Hypocone in M^ and M^ rudimentary." This is a fairly clear 

 distinction from any Torrejon specimen known to me. The species 

 montanensis may be distinguished by having the hypocones of M^~^ 

 slightly smaller than the smaller variants of other known species. 

 If tliis be made a generic character, however, it would be almost the 

 sole character defining the genus and the genus would be monotypic^ 

 as even Gidley's "Neoclaenodon" silherlingi probably had hypocones 

 proportionately as in the larger species. 



4. "Hypocone . . . wanting in M^; M^ much reduced, suboval in 

 outline with relatively small metacone." Tliis again applies only to 

 a very limited extent to 'W." silherlingi. Furthermore, in the 

 Torrejon species usually (but incorrectly) called C. protogonioides 

 some specimens have corrugatus-like M^ and others that are, never- 

 theless, surely conspecific have M^ almost as in "N." montanensis. 

 C. jerox has relatively larger M^, but the hypocone is often lacking. 

 The character is obviously somewhat variable and when well marked 

 of specific, not generic, character. 



5. Various skeletal characters (all repeated in the extended descrip- 

 tion quoted below) are also given. Here it need only be said that, 

 as Gidley points out, the basic structure is quite as in Claenodon. 

 Some characters, as the fusion of scaphoid and centrale (not, however, 

 considered diagnostic by Gidley) or the broad astragalus (which was 

 considered diagnostic), although apparently fundamental, are indi- 

 vidually variable in C. Jerox. None is more important than the 

 slight structural modification to be expected in smaller and larger 

 species of one genus. 



Matthew (Pale. Mem.) accepts Neoclaenodon as probably valid 

 but rejects all Gidley's characters as not being diagnostic of the 

 genus. He does not clearly redefine it but mentions its smaller 

 size, unreduced premolars, and lack of heavily rugose enamel. The 

 smaller size (about 25 percent) is surely not a generic character. 

 The supposed difference in premolar reduction is probablj^ subjective, 

 as already suggested: Matthew says the premolars are less reduced 

 than in Claenodon, and Gidley says they are more reduced. They 

 seem to me to be about the same, taking each supposed group as a 

 whole. The rugosity of the enamel is about the same proportionately 

 in "A^." montanensis as in C. jerox but is probably less in C. ''pro- 

 togonioides.'' 



Matthew's acceptance of Neoclaenodon is based on the Torrejon 

 species that has generally been called Claenodon protogonioides. 

 This name is not applicable in tliis way, as it belongs to a Puerco 

 species (probably of the genus Protogonodon) , and Matthew proposes 

 a new name (Pale. Mem., unpublished at the time this was writ- 



