THE MICROSAURIAN FAMILY TUDITANID^. 97 



the ventral scutellas as a family character, the genus will be in the family Tuditan- 

 idae, but the evidence on this point is negative. For the present we may place the 

 genus only provisionally in the family Tuditanidee. The arrangement will undoubt- 

 edly require revision later. 



Erpetosaurus radiatus Cope, 1874. 



Cope, Trans. Amer. Phil. Soc, xv, p. 273, 1874. 



Cope, Geol. Surv. Ohio, 11, pt. 11, pp. 394-395, pi. xxvii, fig. i; pi. xxxiv, fig. 3; text-fig. 10, 1875. 



MooDiE, Bull. Amer. Mus. Nat. Hist., xxvi, p. 348, pi. ixii, fig. i, 1909. 



Type: Specimen No. 8600 G, American Museum of Natural History. 

 Locality and horizon: Linton, Ohio, Coal Measures. (Plate 25, fig. i.) 

 Cope originally described this species from a portion of a skull. He (123) char- 

 acterized the form as follows: 



"The marked character of this form is seen in the very anterior position of the orbits 

 and the contraction of the muzzle. The orbits are large and are separated by a little 

 more than their own diameter; their posterior border is in front of a line measuring the 

 anterior third of the length to the supraoccipital crest, and nearly to the line marking the 

 fourth of the length to the quadrate region. The posterior outline of the skull is deeply 

 concave, the quadrate angle projecting beyond the occipital condyles." 



The base of the specimen is broken and there is no place for the occipital condyles. 

 Unless the specimen has been mutilated since Cope studied it, the occipital condyles 

 are not present. 



The restoration of the skull given in figure 22, B varies but little from that given 

 by Cope in 1875. The elements are practically as he represented them. 



The premaxillae are small and lie in the usual relations to the other elements. 

 Minute conical teeth are present as impressions. They are quite similar to the teeth 

 found in other Microsauria. The nasals are nearly square and form the inner boun- 

 dary of the somewhat oval nostril, which is represented by a depression in the coal. 

 The frontal is elongate. It is about twice as long as wide. It forms a portion of the 

 inner border of the orbit, the remainder being made up by the prefrontals and the 

 postf rental. The parietals are the largest elements of the skull, but they do not 

 greatly exceed the jugals. Together the parietals form a somewhat obtuse oval 

 in the median region of the skull and they contain between them, in their posterior 

 third, the small circular pineal foramen. The postparietal forms the posterior 

 boundary of the skull. The prefrontal forms the anterior border of the orbit and 

 is triangular in shape. The lacrimal is not identified. The maxilla is an elongate 

 element the boundaries of which are uncertain, though probably somewhat as given. 

 The postfrontal and the postorbital form the posterior boundary of the orbit, 

 inclosing between them the anterior projection of the squamosal. The squamosal is 

 an elongate element and is acuminate at each end. The tabulare is a large element 

 lying lateral to the postparietal. The jugal is a very elongate element, apparently 

 acuminate anteriorly. The quadra to jugal is small and elongate. The supratemporal 

 is definitely bounded and its limits are as indicated (fig. 22 B), being a large element 

 which forms the quadrate angle. 



There are two other specimens of this species in the collections and a fragment 

 of a fourth which it is difficult to make out. Cope identified and figured one of these 



