PALEOCENE MAIVIMALS OF CENTRAL UTAH — GAZIN 39 



but are appreciably larger, even than in Tetraclaenodon^ being about 

 the size of those in Protogonodan stenognathus. The trigonids of 

 these teeth show the paraconids to be entirely lingual in position, as 

 in Tetraclaenodon^ but better developed and perhaps not go close to 

 the metaconid. The paraconid is more lingual and not so far forward 

 as in Protogonodon material, and the crest from the paraconid to 

 the anterior wall of the protoconid is higher, closing the trigonid 

 basin anteriorly. Moreover, the talonid portion of the lower molars 

 is relatively narrower than in Protogonodon pentacus with the basin 

 restricted transversely, being more nearly comparable to the form of 

 the talonid in the first two lower molars of Tetraclaenodon. A 

 relatively narrow talonid was noted in the lower molars of the large 

 Protogonodon hmibetovius. 



A jaw portion with M,, No. 16218, and an isolated portion of a 

 lower molar in the collections from the Dragon level are considered to 

 belong to Z>. faracrt^odus. These closely resemble the lower teeth 

 from the Wagonroad level referred to Z>. paracreodus. 



Table 6. — Measurements {in millimeters) of upper teeth of Desmatoclaeuus 

 paracreodus (C7. 8. N. M. No. 16201) 



Measurement M' I M' M' 



Anteroposterior diameter _ 8.4 8.1 6.2 



Transverse diameter 



' Greatest transverse diameter. 



Genus ECTOCONUS Cope 



ECTOCONUS SYMB0LUS,2i new species 



Type.— Right maxillary portion, U.S.N.M. No. 16189, with M}, 

 M-, and part of P^. 



Horizon and 1-ocality. — Wagonroad Paleocene, Dragon Canj^on, 

 Emery County, Utah. 



Speci-fic characters. — Molars smaller than in Ectoconus ditrigonus. 

 Premolars relatively larger. No "protoconule" on P*. Protostyle on 

 upper molars weak. Parastyle on M- weak. Parastylid absent or 

 weakly developed on lower molai"S. 



DescHption. — Several specimens from the Wagonroad horizon, in- 

 cluding maxillae and jaws with two teeth each, are found to represent 

 a, new species of Ectoconus. The molar teeth are seen to be dis- 

 tinctly smaller than in E. ditrigonus, hence much smaller than in 

 E. niajuscvlus. The premolars, however, are relatively larger and the 

 anterior lower premolars, as indicated in referred specimens, are 

 .actually larger than in E. ditngonus. 



-^ai'^t&oXov, clue, in allusion to its iniportanee in determining the age of the Wagonroad horizon. 



