1877.] 1"1 [Cope. 



This interesting fossil was found in the Triassic formation of Texas by 

 my friend Jacob Boll. The cranium and vertebrae were discovered in such 

 relation as render it evident that they were parts of one animal. 



Strigilina guri,eiana, Cope, sp. nov. 



This species is known by a single jaw or tooth in complete preservation, 

 which was found, like the type of the genus S. Ungumformis* near Dan- 

 ville, 111., by Mr. Gurley. 



The tooth is quite small, its length only equaling the width of the 

 known tooth of S. lingumformis. It is also narrower in proportion to the 

 length. The root and the cutting edge are turned in opposite directions 

 as in the other species. The principal difference between the two is seen 

 in the character of the transverse ridges or crests of the oval face. There 

 are two crests less, or five, with a delicate basal fold, making six, 

 while, counting the fold there are eight in S. lingumformis. The anterior 

 ridge is transverse ; the others slightly convex backwards, and all are 

 equidistant and uninterrupted, which is not the case in the older species. 

 They are also of different form, being distinct ridges with anterior and 

 posterior faces similar. In 8- linguceformis the anterior face only is verti- 

 cal, the posterior descending very gradually, the whole forming a series of 

 steps. Length of ridged face .0060 ; width anteriorly .0035 ; width pos- 

 teriorly .0020. 



This species is dedicated to William Gurley, of Danville, Illinois, to 

 whose zeal science is indebted for the species from that locality described 

 in this and other papers. 



Twenty species have now been obtained from the Clepsydrops shales, the 

 exact geological position of which remains to be accurately determined. 

 Dr. "Winslow informed me that they are the bed No. 15 of Prof. Bradley's 

 section of the Carboniferous rocks of Vermilion county, Illinois. This 

 places them near the summit of the Carboniferous series, below two thin 

 beds of coal (which word is misprinted " coral " in my last paper, Proceed. 

 Amer. Philos. Soc. 1877, p. 63). I am now informed that this portion of 

 Prof. Bradley's scale is not correct, and that No. 15 occupies a much 

 higher position than he assigns to it. It lies unconformably above the 

 merom sandstone of Mr. Collett, which deposit is above the coal meas- 

 ures and unconformable to them. The stratigraphical evidence is thus 

 confirmatory of that derived from paleontology, that the Clepsydrops 

 shale occupies a position in the scale above the coal measures. 



Ctenodxjs pusilltjs, Cope, sp. nov. 



Form narrow, the width of the base about equal to the depth. The 

 eoronal portion is narrower than the base, because the inner face is 

 oblique, forming an acute angle with the inferior plane. There are but 

 four crests, of which the two longer are directed in one direction, and the 

 two shorter in another. The interior ones of both pairs form a continuous 



* Proceedings Amer. Philos. Soc. 1877, p. 52. 



