30 



Annals of the Carnegie Museum, 



deep lachrymal pits. The occiput is high, with large and deep lateral 

 excavations, which are situated below and back of the posttemporal 

 and lambdoidal crests. The occipital condyles have rudimentary acces- 

 sory facets for the atlas. The tympanic bulla is of very large size and 



Fig. 4. Side view of skull of Phenacoccclus typus. \ nat. size. Type, No. 1263. 



extends much below the postglenoid process.' The sagittal crest is 

 low. The orbit is well rounded. The infraorbital foramen is situated 

 above the anterior part of P±. The nasals greatly overhang in front. 

 The metatarsals are shorter than the metacarpals. 



The genus belongs to the family Agriochoeridse, 8 revealing affinities 

 to Leptauchenia and Cyclopidius. The type specimen is about one 

 fourth larger than Leptauchenia. 



, , Type. Paratype. 



Measurements. ,.. yv ' , ,., '*\ , 



(No. 1263.) (No. 1276) 

 mm. mm. 



Greatest length of the skull 185* 192 



Distance from condyles to incisors 170* 175 



Distance from posterior border of orbit to incisors 102* 98 



Distance from posterior border of orbit to condyles 80 87 



Length of alveolar border of the maxillary 95* 92 



Distance from the posterior end of the alveolar border of the 



maxillary to the condyle 75 f 81 



s According to the recent studies of C. W. Gilmore {Proceed. U. S. Nat. Mu- 

 seum, Vol. XXXI., pp. 5[3-5H, 1906), and Earl Douglass (Science, Mo\. XXIV., 

 pp. 565-567, 1906) ; and also according to the Catalogue of the Fossil Vertebrata 

 of North America, by O. P. Hay, it appears that the family name Agriochceridce must 

 be used in speaking of this group instead of the name Oreodontidce, which has been 

 heretofore almost exclusively used. 



* Indicates approximate measurements. 



f The fore and-aft crushing of the type skull in this region causes this difference 

 in measurements. 



