346* CALIFORNIA ACADEMY OF SCIENCES. 



PKOTYPUS. PTYCHASPIS. 



- SENECTUS Wai., 1886; Bull. U. S. Geol. Survey No. 30, p. 213, pi. 31, 



figs. 2, 2 a-c. 



- SENECTUS Wai., 1890; 10th Kep. U. S. Geol. Survey, p. 655, pi. 98, 



fig. 7, 7 a-c. Olenellus zone. 



SENECTUS var. PARVULUS. For other references see Bathyurus par- 



vulus. Walcott 10th Rep. U. S. Geol. Survey, p. 568, refers it to 



a variety of P. senectus, 

 PTEROCEPHALIA Roemer, 1852; Kreid. von Texas, p. 93. 



Conocephaliles (PterocephaUa) LATICEPS H. & W., 1877; U. S. Geol. 



Expl. 40th Par., vol. 4, p. 221, pi. 2, figs. 4-7. Pogonip Mt., 



White Pine, Nev. 

 Ptychoparia (PterocephaUa) LATICEPS Wai., 1884; Pal. Eureka Dist. 



Mon. U. S. Geol. Survey, vol. 8, p. 59. Richmond Mine Shaft, 



Ruby Hill, northeast side of caiion, and in the Hamburg belt, 



Nev. 

 Ptychoparia (PterocephaUa) OCCIDENS WaL, 1884; Pal. Eureka Dist. 



Moii. U. S. Geol. Survey, vol. 8, p. 58, pi. 9, fig. 21. Hamburg 



Ridge, Nev. 



SANCTI-SABJE Roemer, 1849; Texas, p. 421. San Saba Shale, Texas. 



SANCTI-SAB^E Roemer, 1852; Kreid. von Texas, p. 93, pi. 11. 

 PTYCHASPIS Hall, 1863; 16th Rep. New York State Cab. Nat. Hist., p. 170. 



BARABUENSIS Winch., 1864; Am. Jour. Sci., 2d series, vol. 37, p. 230. 



Sauk Co., Wis. Taconic. 



Arionellus CYLINDRICUS Bill., 1865; Pal. Foss., vol. 1, p. 406, fig. 385. 

 Point Levis, Quebec. 



Conoceph (Ptychaspis) EXPLANATUS Whitf., 1880; Ann. Rep. Geol. 

 Survey Wisconsin, 1879, p. 48. Hudson, Wis. Taconic. 



Conoceph (Ptychaspis?) EXPLANATUS Whitf., 1882; Geol. Wisconsin, 

 vol. 4, p. 181, pi. 1, figs. 27, 28. 



Dicellocephallns GRANULOSUS Owen, 1852; Rep. Geol. Survey Wiscon- 

 sin, Iowa and Minnesota, p. 575, pi. 1, fig. 7. Taconic. 



cjranulosa Hall, 1863; 16th Rep. New York State Cab. Nat. His., p. 



173, pi. 6. figs. 33-40. Trempaleau and Miniska. (SeeP. striata.) 



granulosa Whitf., 1878; Ann. Rep. Geol. Survey Wisconsin, 1877, 



p. 34. 



- granulosa Whitf., 1882; Geol. Wisconsin, vol 4, p. 185, pi. 1, fig. 24. 



- GRANULOSA Whitf., 1882; Geol. Wisconsin, vol. 4, p. 185, pi. 1, fig. 24. 

 Dicellocephalus MINISCAENSIS Owen, 1852; Rep. Geol. Survey Wiscon- 

 sin, Iowa and Minnesota, p. 574, pi. 1, figs. 3, 12; pi. 1 a, figs. 

 4, 5. Trempaleau and Miniska, Wis. 



MINISCAENSIS Hall, 1863; 16th Rep. New York State Cab. Nat. Hist., 



p. 171, pi. 6, figs. 41-46; pi. 10, figs. 21, 22. 



MINUTA Whitf., 1878; Ann. Rep. Geol. Survey Wisconsin, 1877, p. 55. 



At Robert's Shore, St. Croix Co., Wis. Taconic. 



