214 



is deep, and continued to near the symphysis. The cotylus of the articular 

 bone is presented largely backward. 



The preraaxillary is a large oval plate, gently convex on the outer side, 

 and of greater vertical than transverse extent. It differs from that of Portheus 

 in lacking the condyle on the superior border. In the best-preserved speci- 

 men, a large piece is broken from its posterior alveolar border ; in that which 

 remains, nine alveoli remain. 



In two of the specimens, the anterior part of the cranium is preserved. 

 The anterior part of the ethmoid is broad and convex above, and rapidly 

 contracts to an acute, flat apex. Laterally, it overhangs the fossa in which 

 the anterior maxillary condyle enters, and furnishes a flat surface for the 

 posterior condyle of the same bone. The vomer is excavated laterally in 

 front, so as to be somewhat cross-shaped, the apex being rather produced. 

 It is edentulous. 



Measurements. 



M. 



No. 1, depth of the prcmaxillary 0.054 



No. 1, depth of the maxillary at the middle 0. 025 



No. 1, depth of tho triangular hone of tho palate : 0. 03S 



No. 1, depth of the symphysis of the mandihuli 0. 02G 



No. 2, length of three anterior vertebra; 0. 040 



No. 2, diamoter of one anterior vertebra 0. 010 



No. 2, depth of the dentary : 0.041 



No. 2, depth of tho symphysis 0.020 



To. 2, width of the ethmoid above 0. 0155 



No. 2, width of the crauium at the prefrontal facets 0.022 



No. 2, length of the muzzle to the prefrontal facets 0.023 



A third specimen consists of some vertebra; and portions of the cranium; 

 tin 1 latter including the dentary. maxillary, part of the prcmaxillary, the 

 palatine and vomerine bones, compressed into a mass by pressure, the 

 separate pieces preserving nearly their normal relations. From the hitter, 

 the following characters may be derived: 



Palatine bones toothless: teeth of both maxillary and dentary with 

 compressed crowns, which are longer than wide at base, and closely placed; 

 those of the dentary twice as large as those of the maxillary. Maxillary bone 

 proximally deep; dentary shallower; the maxillary with elongate suture with 

 the preraaxillary behind. 



The teeth are equilateral, without intermargind groove or barb, and with 

 smooth enamel surface, or only minutely striate under the microscope. 

 A series of larger foramina extends along the alveolar margin of the maxil 



