2y0 CALIFORNIA ACADEMY OF SCIENCES. 



CERAUEUS. 



[Cheirurus) xiagarexsis Hall, 1879; 28tli Hep. New York State Mus. 



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

 Syn., Cheirurus bimucronatus (Murch.) Eoemer; Die Sil. Fanua W. 

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



XIAGAREXSIS Hall, 1882; 12tli Ann. Eep. Geol. Nat. Hist. Indiana, 



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

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



fig. 11. English Head. Hudson. 



Cheirurus XCPERUS 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 probablj" of other genera. The genus Ceraurus 



belongs to the Trenton, Hudson and Niagara periods. Table 



Head, N. F. 

 • PLEUREXANTHEMU8 Greeu, 1832; Monthly Am. Jour. Geol., vol. 1, p. 



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

 pleurexaxthemus Green, 1832; Mou. Tril. N. A., p. 84, fig. 10, pi. 



1, cast 33. 

 Syn., Calymene hucklandi Anthony, 1838; Am. Joiir. Sci., 1st series, 



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



pleurexaxthemds 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. 



pleurexaxthemus Emmons, 1855; Am. Geol., vol. 1, p. 217, pi. 15, 



figs. 1 a-k. 

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

 188. 



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



p. 132. 



pleurexaxthemus Wal., 1875; Annals Nat. Hist. New York, vol, 11, 



p. 155, pi. 11. 



pleurexaxthemus Wal., 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, Mingau Island. Chazy and Hudson. 



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

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



? pustulosa Hall, 1847; Pal. New York, vol. 1, p. 246, pi. 61, fig. 2 a-h. 



Watertown, N. Y. Trenton. 



KARUS Wal., 1877; Advanced sheets 31st Eept. New York State Mus. 



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



