716 E. C. CASE 



shows many points of interest. In all the single teeth, as described by Cope, 

 they are attached to a portion of the jaw and unaccompanied by any other 

 teeth, but there is posterior to the tooth a cavity which, as shown by the 

 more perfect jaw, accommodated a second tooth larger even than the first. 

 In the fragment of the jaw there are, first, three quite small teeth, and 

 then, supported by a swollen portion of the rim, there are two very large 

 canine teeth ; posterior to these, three teeth about equal in size to those ante- 

 rior to the canines, and then five smaller ones. As both ends of the piece 

 are incomplete, it is certain that there were more teeth than here recorded. 

 Several differences from Clepsydrops and Dimetrodon are apparent : first, the 

 anchylosis of the teeth to the jaw, instead of being inserted in well defined 

 alveoli ; second, the presence of two enlarged canines instead of one, and 

 third, the possible absence of the diastema anterior to the canines ; for in the 

 Dimetrodon the anterior teeth of the maxillary decrease to small size imme- 

 diately and the notch of the diastema begins just anterior to the canine and 

 below the external nares, but here, though the anterior tooth is almost below 

 the nares, there is no sign of the beginning of the notch, if any existed. 

 The teeth are all more or less rounded in section and show no sign of a cut- 

 ting edge. In general appearance the jaw is much like that of the Pelyco- 

 saurians ; i. e., with a thin outer wall and a heavy shelf-like dentigerous 

 edge. 



Associated with the fragments of the upper jaws are several portions of 

 the lower jaws showing the symphasial region. Some of the anterior teeth, 

 about the third and fourth, seem to have been slightly larger than the others, 

 but as such a small part is preserved it is impossible to say definitely. These 

 fragments may have belonged to the genus Clepsydrops, and, indeed, the 

 fragments of the upper jaws also. 



[Nos. 6524 and 6525.] 



UNNAMED SPECIMENS. 



Besides the specimens named and described by Cope there 

 are present in the collection many isolated bones from different 

 parts of the skeleton which cannot be identified with certainty as 

 belonging to any of the forms described ; that they belong to 

 some of them is practically certain. The fact that the bones are 

 nearly always found isolated and generally in a fragmentary 

 condition prevents any attempt at a restoration of the skeleton, 

 but their resemblance to corresponding bones from the Texas 

 deposits makes it probable that the animals from the two regions 

 did not differ materially in form. One fact is noticeable, the 



