136 



each side to each nareal orifice, and the intervening longitudinal ridge is deeply 

 fissured hy a parallel groove. The parietal fijntanellc is entirely in the parietal 

 bone. The postfrontal is massive. 



The quadrate bone presents a very prominent internal angle, as in other 

 Clidastes, and has the posterior hook much prolonged downward and inward, 

 with a button and surrounding groove on the inner side of one, but none on 

 the other. The stapedial pit is a narrow oval, as in Lwdon proriger. The 

 median posterior ridge is prominent, and united with the distal internal longi- 

 tudinal, extending to the narrow posterior angle of the distal articular face. 

 The internal ridge is prominent, dividing the internal face of the bone into 

 two planes, the posterior of which is but little concave along its upper poste- 

 rior border {i. e., on the inner side of the hook) ; this region is very concave 

 in some species of the genus. There is a strong transverse obtuse ridge, which 

 extends along the outer side, turning backward into a rough process opposite 

 the origin of the base of the ala. Between this and the distal articular face 

 is a subtriangular rugose area. The palatine bone has its anterior and poste- 

 rior extremities broken away, the fragtnent supporting six teeth. The bone 

 is flat, much as in the species of Plalecarpus, the tooth-line passing from the 

 inner margin behind to the outer before, the roots being more exposed on the 

 external side ; the external process is stout. The crowns of the palatine 

 teeth are curved, with lenticular section, one face being much more convex 

 than the other ; the enamel is shallowly striate-grooved. 



The articular faces of the cervical vertebrce are all transversely oval, not 

 much depressed ; those of the dorsals are also transverse, but less so than the 

 cervicals. Five cervicals and nine dorsals are preserved. The hypapophyses, 

 both fixed and free, are very large and stout. The odontoid is large and prom- 

 inent, and deeper than long. The diapophyses are short, and send a narrowed 

 extension forward to the rim of the cup on all the cervicals and three dorsals. 

 The vertical portion of their surfaces diminishes anteriorly as the horizontal 

 extends, till, on the axis, it is horizontally subtriangular in outhne. . The 

 zygosphen is smaller on the anterior than the posterior vertebra; ; on the 

 latter, the zygantrum possesses special facets for it. The cups, especially 

 of the dorsals, are emarginate for the neural canal. A smooth band borders 

 tli(; circumference of the ball in front. The surfitce, in general, is smooth, 

 will) rugose lines and grooves extending to the articular face of the fixed hypa- 

 [M)pliysis and ;i|)c.\ of flic iVcf, and on I lie upper rool-likr smlacc ol ilir [mjs- 



