360 CALIFORNIA ACADEMY OF SCIENCES. 



TRINUCLEUS. ZACANTHOIDES. 



BELLULUS Ulrich, 1878; Jour. Ciuciuuati Soc. Nat. Hist., vol. 1, p. 



99, pi. 4, fig. 2. 

 Nuttainia concentrica Eaton, 1832; Geological Text Book, p. 34, pi. 



1, tig. 2. Trenton and Hudson Groups of New York, etc. 

 Syn., Trilobiie Bigsby, 1825; Annals Lyceum Nat. Hist. New York, 



Tol. 1, pt. 2, p. 214, pi. 15, fig. 1. 

 Cry})tolithus tessellattis Green, 1832; Monthly Am. Jour. Geol., vol. 1, 



pi. 1, fig. 4. 

 Cryptolithus tessellaius Green, 1832; Mou. Tril. N. A., p. 73, cast 38, 

 pi. 1, fig. 4. 



CONCENTRICA Hall, 1847; Pal. New York, vol. 1, pp. 249, 255, pi. 65, 



figs. 4 a, b; pi. 67, figs. 1 a-h. 

 CONCENTRICA Emmons, 1855; Am. Geol., vol. 1, pt. 2, p. 212, pi. 17, 



fig. 1. 



CONCENTRICA Chapman, 1858; Canadian Jour., vol. 3, p. 514. 



CONCENTRICA Bill., 1861; Geol. Vermont, vol. 1, p. 300, tig. 215. 



CONCENTRICA Miller, 1874; Cincinnati Quart. Jour. Sci., vol. 1, p. 126. 



Zacanthoides Wal., 1887; Am. Jour. Sci., 3d series, vol. 36, p. J 65. 



eatoni Wal., 1889; Proc. U. S. Nat. Mus., vol. 12, p. 45. Washington 



county, N. Y. 



eatoni Wal.; 10th Eep. U. S. Geol. Survey, p. 646, pi. 94, fig. 6. 



Olenellus zone. 

 Dkellocephalus? flagricauda White, 1874; Prelim. Kep. Invt. Foss. 



Geog. and Geol. Survey West 100th Mer., p. 12. 

 Dicellocephalus? flagricauda White, 1877; U. S. Geog. and Geol. 

 Survey West 100th Mer., vol. 4, p. 60, pi. 3, figs. 8 a, b. Schell- 

 bourne, Schell Creek Eange, Nevada. Ta(?onic. 



Olenoides flagricaoda Wal., 1886; Bull. U. S. Geol. Survey, No. 30, 

 p. 185, pi. 25, fig. 4. 



FLAGRICAUDA Wal., 1888; Am. Jour. Sci., 3d series, vol.36, p. 165. 



Olenoides levis Wal., 1886; Bull. U. S. Geol. Survey, No. 30, p. 187, 

 pi. 25, figs. 3, 3 a. Pioche, Nev. Taconio. 



LEVIS Wal., 1888; Am. Jour. Sci., 3d series, vol. 36, p. 165. 



LEVIS Wal.; 10th Eep. U. S. Geol. Survey, p. 646, pi. 94, figs. 5, 5 a. 



Olenellus zone. 

 Ogygia? spino.sus Wal., 1884; Pal. Eureka Dist., Mon. U. S. Geol. 

 Survey, vol. 8, p. 63, pi. 9, fig. 22. Secret Canon, Nev. Taconic. 

 Olenoides spinosus Wal., 1886; Bull. U. S. Geol. Survey, No. 30, p. 



184, pi. 25, figs. 6, 6 a. 

 Embolimvs spinosus (Eominger) Wal., 1888; Am. Jour. Sci., 3d series, 

 vol. 36, p. 164. 



SPINOSUS Wal., 1888; Am. Jour. Sci., 3d series, vol. 36, p. 165. 



Olenoides typicalis Wal., 1886; Bull. U. S. Geol. Survey, No. 30, p. 

 183, pi. 25, figs. 2, 2 a. Olenelkis zone. Pioche, Nev. Taconic. 

 typicalis Wal., 1888; Am. Jour. Sci., 3d series, vol. 36, p. 165. 



