Ptycha. 



830 



sis). Owen Geol. Wise, 1852, pi. 1, %. 3, 12; pi. 1 A, fig. 4, 

 5 ; from Third Trilobite bed, near fork of Missiskah and Mis- 

 sissippi rivers. Upper Cambrian ? 1. 



rtychaspis speciosus. Walcott. Potsdam Fauna, Sara- 

 O.C,_ i 3 toga Co., N. Y., 1888, fig. 3. See Bull. U. S. G. S. 

 p. 62. Genus confined exclusively to Upper Cam- 

 i4 irian (Potsdam) forraation. To be looked for in 

 Pennsylvania along the South Mountains and Ches^ 

 Wat,lS?8 ^^^ North and South Hill ranges. /. 



Ptychophyllum versiforme. See P. knappi. VIII a, 

 Ptycholepis marshii, Newberry. Monograph of Trias^ 



Ir \ pi. 19. 



•Ae)Yl)erry. U.S.G.S. XIV. 



fishes and plants, in U. S. Geol. Survey, Vol. 14, 1888, page 68, 



