Ptycho. 



834 



I g Saratoga county, N. Y., 1880. 

 ^*^ figs. 5 and 8. See Bull. 30, V. 



type; fig. la, enlarged twice, type of Hartt's C. formosus. 

 Lower Cambrian {Saint John) formation. L. C. 



Ptychoparia rogersi. Walcott, Bulletin No. 10, U. S. G. 

 ^2 w S. page 47, plate 7, fig. 2. Natural size, type 

 ' specimen. (Species only known by central plate 

 of head, and in two specimens, portions of thorax. 

 Middle Cambrian {South Braintree) argillite, 

 Hayward's quarry, Mass. M, (7. 



Ptychoparia (A) saratogensis. Walcott, Potsdam Fauna, 



S. G. S. page 62. Upper Cam- 

 brian {Potsdam) formation. To 

 be sought in Pennsylvania along 

 the South Mountain, and the 

 Chester Valley N. and S. Hill 

 ranges. /. 



Ptychoparia striata. Barrande ; used by Walcott, in Bulle- 



plate 6, fig. 4. 

 taken from Bar- 

 rande, to discuss 

 the genus. 

 Lower C a m - 

 brian of Bohe« 

 mia. Z. C, 



Ptychoparia subcoronata, Hall and Worthen. L. C. 



Ptychoparia tener. ( Conocephalites tener and neglectus^ 



Hartt, 1868, 



L.C. '"^ "" 5 Acad. Geol. 



Dawson, 2d 

 ed. pp. 652, 

 654. (Wal- 

 cott, Bulletin, 



