1896.] Geology and Paleontology. 303 



edge of the ectopterygoids in Pariasaurus and Pariotichus, but not in 

 Elginia or Empedias. A character of the American genera is the 

 weakness of the attachment of the basioccipital to the sphenoid. The 

 basioccipital is lost from the only known specimen of Elginia, and the 

 sphenoid projects freely below it in Pariasaurus, Tbe roof of the 

 mouth in this order is a good deal like that of the Lacertilia, lacking 

 the palatine foramen. 



The order Cotylosauria was defined by me in the AMERICA* Nat- 

 uralist for 1880, p. 304, and in 1889 (October). In 1889 (Transac. 

 Roy. Soc. London, p. 292), Prof. Seeley gave it the name Pariasauria. 

 In my Syllabus of Lectures on Vertebrate Paleontology (1891, p. 38), I 

 arranged the group as a suborder of the Theromora. In 1892 (Tra?is- 

 Amer. Philos. Soc, p. 13, PL I), I again regarded the Cotylosauria as 

 an order, and described the characters of the skull in three of the gen- 

 era, and gave figures of them. 



Seeley has objected to the reference of the genera Pariasaurus and 

 Empedias to the same order, on the ground that the elements connect- 

 ing the supraoccipital and the quadrate rest on the occipital elements 

 in the latter, while they are elevated above them in the former. This 

 character would not, however, define orders, as both conditions are 

 found in Lacertilia ; but might distinguish families within an order. 

 However, Seeley's description and figure of the occipital region in 

 Pariasaurus bainii 3 show that the structure only differs from that of 

 the Diadectidae in the presence of a large foramen between the supra- 

 occipital and exoccipital bones on each side. 



The known species of the Cotylosauria range in dimensions from that 

 of the South American Caimans (Chilonyx, Pariasaurus sp.) to that of 

 the smaller Lacertilia, e. g., Eumeces quinquelineatus (Isodectes and 

 Pariotichus sp.). They range from the Coal Measures to the Trias, 

 inclusive, and have been found in South Africa, North America and 

 Scotland. A single genus has been found in the Coal Measures of 

 Ohio, which is represented by a species which I called Tuditaum puw- 

 tulatus. 6 It is of small size, and as the maxillary teeth are of equal 

 length, I cannot distinguish it from Isodectes, which belongs to the 

 Pariotichidse. The other species which were referred to Tuditanus are 

 Stegocephalia. 7 This is the first identification of a true reptile in the 

 Coal Measures. 



5 Philos. Transac. Roy. Soc. 1892, p. 326, PI. XVIII, Fig. 2. 



•Transac Amer. Philosoph. Society, April, 1874, separate p. 11. Report Geol. 

 Survey of Ohio, 1875, Paleontology, p. 302, Plate XXIV, fig. 1 (erroneously 



i Proceeds. Amer. Philos. Soc., 1871, p. 177. 



