18 



PROCEEDINGS OF THE NATIONAL MUSEUM 



pentacus from the Puerco but exhibit more rugose enamel. The para- 

 conid, which is preserved in only the first two molars, is more lingual 

 in position and not so distinct from the metaconid. The cusps around 

 the talonid, however, though low, are somewhat more distinct from 

 those adjacent than in P. pentacus, with less development of a crest 

 ■and basin. The trigonid portioiis of the teeth are somewhat more 

 elevated witli respect to the talonids than is usual in P. pentacus. 



In the reduction and position of the paraconid and in the rugosity 

 of the enamel the Dragon form makes a definite approach toward the 

 condition seen in the Torrejon specimens referred to Claenodon cor- 

 rugatus {C. ferox). The paraconid in Mg, and perhaps Mi, of P.? 

 spiekeri is better developed and more distinctly sejiarated from the 

 metaconid than in C. comtgatus although it is placed nearly as far 



Figure 9. — Protogonodon? spiekeri Gazin: Right ramus of mandible with M\, M2, and 

 part of M3 (U.S.N.M. No. 15538), type specimen, lateral and occlusal views, X l}i 

 Dragon Palcocenc, Utah. 



lingually as in the Torrejon material. The union or ridge between 

 the protoconid and metaconid is simple and not double as frequently 

 seen in the more coarsely rugose teeth of Claenodon con-ugatus. On 

 the talonid the hypoconulid is more distinct from the entoconid, 

 wliereas in C. cornigatus these two form a more conspicuous ridge, 

 which usually continues with the cingulum around the hypoconid. 

 The cusps in general arc lov^-er and more distinct than in Claenodon, 

 with a less distinctly basined talonid, with fewer accessory cuspules, 

 and a finer quality of rugosity. 



M;, in the type, though incomplete, is much less elongate than in 

 ■C. con-ugatus, as indicated by the spacing of the metaconid, entoconid, 

 and hypoconulid. 



