PERMIAN VERTEBRATES 713 



Length centrum larger caudal - - - - .oi4 m 



Width do. ........ .008 



Depth do. -------- .008 



Length smaller caudal ----- .010 



Depth centrum do. ------ .007 



Width do. -------- .007 " 



[Nos. 6530 (type specimen), 6531, and 6578.] 



Clepsydrops pedunculatus Cope. Plate II, Figs. 4a, 4b, 4c, 4d; 

 Figs. 50, $b, $c, $d. 



Clepsydrops pedunculatus Cope, 1877, Proc. Am. Phil. Soc, 

 p. 63. 



This genus was established on two vertebras, a third cervical, and an ante- 

 rior caudal, regarded by Cope as a dorsal. 



" Both differ from corresponding vertebrae of C. colletti and C. lateralis 

 (this is evidently a slip on the part of the describer ; there is no C. lateralis ; 

 C. vinslovii is evidently referred to, as it was the only other species of the 

 genus described at this date) in having elongate diapophyses for the attach- 

 ment of the ribs. These are present in the other species, but are either very 

 short, or sessile. The third cervical has a broad reverted anterior lip-like 

 margin of the anterior articular face, which resembles the corresponding part 

 in C. lateralis (vinslovii) in not being produced below. The median line is 

 keeled, and there is a shallow longitudinal groove on the upper part of the 

 sides. The posterior articular face is regularly funnel shaped. The diapo- 

 physes are very stout, and are directed a little downwards and strongly back- 

 wards. The articular faces are single, look downwards and outwards, and 

 are wide above, and narrow below. The base of the neural canal is deeply 

 incised, as in the other species." 



MEASUREMENTS. 



!antero-posterior - - - .015 m 



transverse - - - .0125 

 vertical - - - - .012 



Length of diapophysis above - - - .009 



-rv , r j. , • \ vertical - .008 



Diameter or diapophysis ■< . ,, 



r r J I antero-postenor - .005 



In the description of the supposed dorsal attention is called to the long 

 and slender diapophysis ; it is evident that this is not a diapophysis, but an 

 anchylosed rib with the distal broken portion inclined forward, as is charac- 

 teristic of the anterior caudal ribs of the Rhyncocephalia. Speaking of 

 other portions of the vertebra, the describer says : " There is no recurved 

 rim of the articular extremities, but the surface does not pass regularly into 

 the foramen chordae dorsalis, but by an abrupt descent at its mouth. The 



