16 



PROCEEDINGS OF THE NATIONAL MUSEUM 



than in Conoryctes coirvma but distinctly larger than in Onychodectes 

 tisonensis. The Dragon form is about intermediate between these two 

 species in degree of hypsodonty. P* is not so nearly molariform 

 as in C. convrrm and has the lingual portion more compressed antero- 

 posteriorly. The protocone and deuterocone are prominent conical 

 cusps, and the tritocone, though damaged, is seen to be but weakly 

 developed as compared to the other two cusps. The lingual portion 

 of this tooth does not appear crescentic; nevertheless, a low crest 

 or cingulum extends along the posterior portion between the deutero- 

 cone and tritocone. 



The paracone and metacone in the first two molars, as far as pre- 

 served, are seen to be conical and low and are separated from the 



outer margin of the teeth by 

 a heavy cingulum. The meso- 

 style, though present, is not so 

 strongly developed as in C. 

 comma. It is absent in 0. tiso- 

 nensis. The anteroexternal and 

 posteroexternal angles of the 

 teeth are more rounded than in 

 O. tisonensis and do not exhibit 

 styles at these points as in the 

 Puerco form. 



The anteroposterior diam- 

 eters of the upper teeth, P* to 

 M^, are approximately 7.5, 8.2, 

 and 7.4 mm., respectively. A.nj 

 transverse measurements would 

 be highly arbitrary. 



The lower jaw fragment. No. 

 15722, with a molar tooth, ap- 

 parently Ml, may represent Conoryctella dragonensis, although it is 

 from an individual somewhat smaller than the type. The tooth is about 

 intermediate between O. tisonensis and C. comma in hypsodonty but 

 apparently a little nearer O. tisonensis in size. The trigonid of the 

 tooth possesses a moderately developed paraconid situated much as 

 in Ml of O. tisonensis. The heel or talonid, though partially ob- 

 scured by matrix, is relatively broad, appears to be deeply basined 

 and to have a somewhat cuspidate crest, approaching the condition 

 seen in C. commi/i. 



The two lower molars, No. 16173, added to the collection in 1939, 

 exhibit an arrangement of the cusps around the margin of the talonid 

 very much as in Onychodectes., without the greater number of acces- 

 sory cuspules seen in Conoryctes. The teeth are relatively a little 



Figure 8. — Conoryctella dragonensis Gazin: 

 Maxillary portion with P^-M^ (U.S.N.M. 

 No. 15704), type specimen, lateral and oc- 

 clusal views, X 2, Dragon Paleocene, Utah. 



