Cope.] 164: [May 15, 



named the lieel of the molars is larger than in the two others, approach- 

 ing remotely the genus Empedias. The D. latibuccntus difiers from the 

 D. sideropelicus in the smaller number of molar teeth, and smaller and 

 more numerous caniniform teeth. 



BOLBODON TENUITECTUS, gen. et sp. nov. 



Char. gen. — Molar teeth without external heel, and with one median 

 cusp. Cranial bones coossified ; no grooves indicating the sutures of 

 dermal scuta. Internal borders of palatine bones in mutual contact, 

 and dentigerous. 



The dentition of this genus is not diiferent from that of Phanerosau- 

 rus, as described and figured by Geinitz and Deichmiiller.* In that 

 genus, according to these authors, the cranial elements are distinct, 

 the sutures being persistent. In Bolbodon the cranial elements are 

 entirely coossified, excepting only the tabular bone, which is distinguish- 

 able. The nostril is large, and a turbinal bone is visible within it as in 

 Pariotichus. The lateral and inferior bones of the brain case, and the 

 mandible, are not preserved. 



Char, specif. — This species is represented by a portion of the cranium, 

 which includes nearly the entire right side, and a portion of the median 

 part of the superior wall from the tabular border to the premaxillary 

 inclusive. The vomer and the middle portions of the palatines, with the 

 right premaxillary and maxillary bones, are preserved. 



From the middle line at the apex of the vomer to the posterior ex- 

 tremity of the maxillary bone there are alveoli for seventeen teeth. Of 

 these six only are occupied by teeth, which are numbers 5, 7, 10, 12, 13, 

 16. Of these only numbers 5, 13 and 16 have perfect crowns. The 

 skull has been somewhat distorted by pressure, so that the longer axis of 

 the roots and crowns are somewhat oblique to their correct positions. 

 The roots of numbers 5 and 7 are wide-oval in section, and the long axis 

 becomes longer posteriorly up to the number 16, in which it is a little 

 contracted, and where the entire dimensions are smaller. The crown of 

 number 5 is caniniform and acute, is curved backwards as to its anterior 

 face, and has a worn posterointernal face due to the opposing tooth of 

 the inferior series. In number 13 the crown is much more expanded 

 transversely, and the external vertical border is convex medially and 

 incurved above and below. Curved shallow grooves radiate from the 

 external apex downwards and inwards. The crown of the sixteenth 

 tooth is cordiform, with the acute apex upwards. Shallow grooves de- 

 scend from the latter. Like the maxillary teeth the palatines are widely 

 spaced. The sections of their crowns are a wide oval placed longi- 

 tudinally ; apices lost. 



The nostril is large and is rounded subquadrate. The orbit is large 

 and is subround, and its border is not notched as in the Diadectes lati- 

 huceatus, nor the superior border dei)ressed as in D. phaseoUiius. Tlie 



*^ittheiliingen min.- gcol. a. prxhist. Museum of Dresden, 1882, p. 10. 



