290 CALIFORNIA ACADEMY OF SCIENCES. 



CERAURUS. 



- (Cheirurus) NIAGARENSIS Hall, 1879; 28th Rep. New York State Mus. 



Nat. His., p. 189, pi. 32, fig. 16. 



Syii., Cheirurus bimucronatus (Murch.) Roemer; Die Sil. Fauna W. 

 Tenn., p. 80, pi. 5, fig. 19. 



- NIAGARENSIS Hall, 1882; 12th Ann. Rep. Geol. Nat. Hist. Indiana, 



, 1881, p. 335,- pi. 34, fig. 16; pi. 33, fig. 10. 



Cheirurus NUMITOR Bill, 1866; Catalogue Sil. Foss. Anticosti, p. 27, 

 fig. 11. English Head. Hudson. 



Cheirurus NUPERUS Bill., 1866; Catalogue Sil. Foss. Anticosti, p. 61, 

 fig. 20. East Point Div. 3. Anticosti group. 



Cheirurus PERFORATOR Bill., 1865; Pal. Foss., vol. 1, p. 287, fig. 275. 

 All the species described from the Quebec group of Newfoundland 

 by Billings are probably of other genera. The genus Ceraurus 

 belongs to the Trenton, Hudson and Niagara periods. Table 

 Head, N. F. 



- PLEUREXANTHEMUS Green, 1832; Monthly Am. Jour. Geol., vol. 1, p. 



560, pi., fig. 10. Trenton and Hudson. 



- PLEUREXANTHEMUS Green, 1832; Mon. Tril. N. A., p. 84, fig. 10, pi. 



1, cast 33. 



Syn., Calymene bucklandi Anthony, 1838; Am. Jour. Sci., 1st series, 

 vol. 36, p, 106, figs. 1, 2. 



- PLEUREXANTHEMUS Hall, 1847; Pal. New York, vol. 1, p. 242, pi. 65, 



figs. 1 a-n; pi. 66, figs. 1, 1 h. Middleville, Trenton Falls, etc., 

 N. Y. 



- PLEUREXANTHEMUS Enimons, 1855; Am. Geol., vol. 1, p. 217, pi. 15, 



figs. 1 a-k. 



Cheirurus PLEUREXANTHEMUS Bill., 1863; Geol. Canada, p. 188, fig. 

 188. 



PLEUREXANTHEMUS Miller, 1874; Cincinnati Quart. Jour. Sci., vol. 1, 



p. 132. 



PLEUREXANTHEMUS Wai., 1875; Annals Nat. Hist. New York, vol, 11, 



p. 155, pi. 11. 

 PLEUREXANTHEMUS Wai., 1881; Bull. Mus. Comp. Zool. Harvard Coll., 



vol. 8, p. 211, pi. 5, figs. 1-6. 

 Cheirurus POLYDORUS Bill., 1865; Pal. Foss., vol. 1, p. 286, fig. 274. 



Table Head, Portland Creek, N. F. 

 Cheirurus POMPILIUS Bill., 1865; Pal. Foss., vol. 1, p. 181, fig. 162. 



Large Island, Mingan Island. Chazy and Hudson. 



Cheirurus PROLIFICUS Bill., 1865; Pal. Foss., vol. 1, p. 285, fig. 273; 



p. 325, fig. 311. Cow Head, N. F. 



V PUSTULOSA Hall, 1847; Pal. New Yqrk, vol. 1, p. 246, pi. 61, fig. 2 a-h. 



Watertown, N. Y. Trenton. 



- IIARUS Wai., 1877; Advanced sheets 31st Rept. New York State Mus. 



Nat. Hist., p. 15. Beloit, Wis. Trenton. 



