Ptyo. 



846 



of the reptile, showing the breast shield, delicate hair-like ab- 



CoKc » 



FaLOJiio 



Vol 



dominal rods, and some of the fan-like neural spines of the 

 backbone. It is of the size of P. pectinatus^ and perhaps be- 

 longs to that species. Coal measures. XIIL 



Ptyonius ? Side view of the head of one of these coal 



measure 



reptiles 



found at 



Linton, 



O. Pal. 



Ohio, Vol. 2, plate 44, fig. 3, natural size. Another cranium 

 is shown on plate 35, fig. 4, also natural size. None of these 

 reptiles have been recognized as yet in Pennsylvania, but there 

 is every reason for expecting their discovery in the roof shales 

 of one or other of our bituminous coal beds. XIII. 



xin. 



Pupa vetusta, Dawson. Acadian Geol. 1868, p. 384, f. 149, 



a minute land shell of the 

 d. W ^^M. Coal age (the first ever 



found in Palaeozoic forma- 

 tions), got from the inside 

 of a rotten tree (calamite) 

 standing erect in the Jog- 

 gins Cliff of the Bay of 

 Fundy. 149 a, natural 

 DawsHTT^cad. Geo!. 1868. P^^^- sise ; b, enlarged 6 times; 



c, apex enlarged; c?, surface marking magnified; quite like 

 the Pupas now living ; all the more remarkable because no 

 other fossil true land shell is known up to the Tertiary strata 

 (1863, Dawsoi.). Found with reptiles; and also in another 

 bed, 1217 feet lower (Group VIII, between coals 37 and 38 of 



