234 



a beak posteriorly, and presents an elevated longitudinal and obtuse ridge on 

 the middle line. This supports a row of nine teeth, five of them having 

 mates. The bone expands at the other end for a squamosal articulation with 

 other elements. The pharyngeal teeth are smaller than the larger dentaries. 



The caudal vertebra are elongate, and much contracted medially ; the 

 rims of the cups are thickened, and the cups themselves very deep. There 

 is a trace of a single median longitudinal groove. The neural and haemal 

 arches are represented by broad longitudinal laminae in the specimens. The 

 vertebras are thus very different from those of the Saurodontidce. 



In a second specimen, with jaws and vertebras, the pharyngeal bone is a 

 tongue-shaped piece, wide and fiat at one end, and contracting to a narrow 

 apex, with subtriangular apex. A series of sixteen teeth and bases extends 

 from near this point backward. The superior half of the dentary bone is 

 almost smooth ; the symphysis quite narrow and acuminate. The cranial 

 bones are marked with radiating ridges, which are delicately denticulate. 



In a specimen represented by a nearly entire vertebral column, we 

 count forty-three vertebras, of which twenty-three support entire haemal 

 arches. The anterior two-thirds of these are the longest of the series ; the 

 centra shortening in both directions, most rapidly to the caudal fin. The 

 middle part of the side of the centrum is entire on all but the last fourteen 

 or fifteen, where it is marked by a deep longitudinal fossa. The dorsal cen- 

 tra are marked with several narrow grooves and ribs laterally. 



There are three series of elongate diamond-shaped scuta on the sides of 

 the abdomen opposite the dorsal vertebras of this specimen. Their surface 

 is radiate and concentrically rugose-sculptured. On the anterior caudal ver- 

 tebras, the neural and haemal laminae are higher in front of the spine than 

 behind it. On the posterior dorsals, there is a short, slender process, project- 

 ing forward from the middle of the centrum below, at right angles to the ribs. 

 Neural spines and ribs slender. 



Measurements of No. 2. 



M. 



Length of the dentary to the twelfth large tooth 0. 0G7 



Depth of the dentary at the first large tooth 0. 005 



Depth of the dentary at tho tenth large tooth 0. 020 



Dept h of the ? pterygoid houe 0. 018 



Thickness of the ? pterygoid bone 0.003 



Ilia meter of tho occipital cot y Ins 0.01-1 



Length of the four anterior cervicals 0. 056 



