the Cretaceous and Tertiary Formations. 451 



This species was apparently about the size of Glidastes inter- 

 medins Leidy, but maj easily be distinguished from it bv its 

 smooth teeth, and the more nearly vertical articular faces of the 

 vertebrae. The present specimens were found by the writer, in 

 the gray shale, near the North Fork of the Smoky Elver,' in 

 Western Kansas. 



Glidastes Wymani, sp. nov. 

 The remains on which this species is based consist of a series 

 of cei-vical and anterior dorsal vertebra?, with portions of the 

 skull and quadrates of the same individual, and portions of 

 another skeleton, including a nearly or quite complete vertebral 

 series from the posterior lumbars to the extremity of the tnil. 

 The two suites of specimens correspond so closelv in size and 

 proportions, as well as in special characters, that tliey mav with 

 comparative safety be referred to the same species. 



The specimens indicate a small reptile, very near Glidastes 

 propyihon in size, but differing from that species in several im- 

 portant particulars. One of the most noticeable of these is the 

 lorm of the muzzle, which in the present example has a short 

 and obtuse extremity, not unlike that of Liodon proriqer Cope. 

 J-he basioccipital has the condyle deep vertically, and onlv a 

 shallow groove on its upper surface for the neural canal. The 

 quadrate has the postero -superior process free at its lower ex- 

 tremity. Just below this, there is a prominent rugose knob, 

 With a deep pit under it, entering from the external border. 



in the cervical vertebrae, the outline of the articular faces is 

 n-ansyerse cordate, the ball of the axis showing a marked differ- 

 ence m this respect from that of Glidastes propython, where it is 

 ''nbpentagonal. The centra of the anterior doreals are elongate, 

 and much constricted behind the diapophvses. The cup here 

 oecomes broader, and the emargination deeper. In the anterior 

 S„ ^'' ^¥. articular faces are a broad vertical oval. The ver- 

 L have deeply concave sides. In the twenty- 

 ■■ ■'' ' 1 where the last rudiment 



and vertical 

 length of the centrum are very 

 ^— „> c^uai. m the median caudals, the centra become com- 

 pressed, the cup is very shallow, and the neural spmes and 

 evrons are directed backward. The posterior caudals are 

 ;r?- ^,°^Pressed, with the cup very deep, the neural spme stiU 

 '^f ' but the chevrons are nearly perpendicular. The entire 

 auaai series, excepting those at the very extremity, have co- 

 '!f «d chevron bones. There are eighty-one caudal vertebrae 

 Preserved, the last fifty being continuous. The terminal ones 

 ^e^ess than one-twelfth of an inch in transverse diameter! 

 's senes would imply that there were considerably more than 



fiftL , "^ icgiun nave aeepiy concav 

 fifth caudal, or vertebra with chevrons ^ 

 « the diapophysis has disappeared, the 

 diameter of the cup, and the length o: 



