93 THE COAL MEASURES AMPHIBIA OF NORTH AMERICA. 



are preserved and prove this element to have had an obtuse posterior border. The 

 sutures bounding the frontals are clear and show that they were small and that they 

 formed a part of the inner boundary of the orbits. The parietal is recognized as a 

 large element, apparently the largest in the skull. Together the parietals form a 

 wide oval inclosing, on the median suture, the circular pineal foramen. The parie- 

 tals are sculptured with coarse radiating grooves and ridges, much after the manner 

 of Erpetosaurtis radiatiis Cope. The pittings present on that form are, however, 

 absent in T. minimus. The sutures bounding the postparietal are tolerably well 

 defined and these show that element to have been rather large and quadrate, with 

 the usual relations. The tabulare is distinct, triangular, and small. It is produced 

 into an angle on the posterior border strongly recalling a similar condition in T. 

 punctulatus. The boundaries of the prefrontals and the upper borders of the max- 

 illae are not clearly ascertained. The lacrimal has not been detected. The post- 

 frontal and postorbital form the posterior boundary of the orbit, although all of the 

 limits of the latter element have not been definitely determined. The position of 

 the supratemporal is well assured, although its entire bovmdaries are not determined. 

 It has the usual relations and joins the parietal broadly. The jugal is broad and 

 widens posteriorly to join the squamosal, which, as usual, forms the quadrate angle 

 of the skull. The sutures bounding the quadrate jugal and the posterior end of the 

 maxilla are not determined. 



There are but two fragmentary vertebrae preserved and an estimate based on the 

 length of these remains gives about 30 presacral vertebras. The structvu-e of the 

 vertebrae preserved can not be ascertained, but the neviral spines appear to have 

 been low and stout. 



There are six elements of the pectoral girdle preserved. These are: the six 

 clavicles, the interclavicle, the coracoid of one side, and the two scapulae. The 

 interclavicle is rhomboid in form and acimiinate posteriorly. It is sculptured 

 with radiating grooves and ridges. It is quite different from the same element 

 in T. punctulatus, in that the base is acuminate, not truncate. The clavicle 

 presents much the same shape as does that element in Erpetosaurtis tabulatus. It is 

 ornamented by a sculpturing of radiating lines which take their origin from the 

 lower external angle as the bone lies in the matrix. The clavicle is somewhat trian- 

 gular in shape and lies close to the skull, but this close approximation of the pecto- 

 ral elements to the cranium is due probably to post-mortem shifting, since the 

 scapulae are shifted backward. There can be little doubt, however, that the pectoral 

 arch was close to the cranium. There is an oval fragment preserved on the left of 

 the specimen which I take to be a portion of the coracoid. The scapula is preserved 

 entire on the left side and is represented by fragments on the right side. It is 

 almost semicircular in form and narrows externally until it is somewhat fan-shaped. 

 There appears to be an ornamentation of lines on the surface of the bone. These 

 lines follow the contour of the anterior border. 



The arm is preserved nearly complete on the left side, and the right side shows 

 the humerus and the forearm. The humeri are unusual in having well-developed 



