284 AMEBIC AN FOSSIL BRYOZOA. [bull. 173. 



Helopora formosa Billings, See Nematopora formosa (Billings). 



Helopora fragilis Plall. 



1852. Helopora fragilis. Hall, Pal. New York, II, p. 44, pi. x\aii, .3a-/. 



1874. Helopora fragilis. Nicholson and Hinde, Canadian Jour. , new ser. , XIV, 



p. 141. 



1875. Helopora fragilis. Nicholson, Pal. Province Ontario, p. 44, fig. 19, 3, oa. 



1888. Helopora fragilis. Ulrich, American Geologist, I, p. 233, fig. 2a-e. 



1889. Helopora fragilis. Miller, North American Geol. Pal., figs. 485o-e, 486 



(p. 308). 



1890. Helopora fragilis. Ulrich, Geol. Sur. Illinois, VIII. p. 642, figs. IHa-,' (p. 



643), pi. xxix, 5o. 

 Clinton: Rochester, New York. 



Niagara: Lockport, New York; Flam borough Head, Ontario. 

 Obs. See also Helopora bellula Billings. 



Helopora f rag-ilis-acadiensis Hall. Not defined. 



1860. Helopora fragilis var. acadiensis. Hall, Canadian Nat. Geol., V, p. 159. 

 Silurian : Nova Scotia. 



Helopora harrisi James. 



1883. Helopora harrisi. James, Paleontologist, No. 7, p. 58, pi. ii, 2-25. 



1889. Helopora harrisi. Ulrich, Contr. Micro-Pal. Cambro-Sil., Part II, p. 45. 

 1893. Helopora harrisi. Ulrich, Geol. Minnesota, III, p. 195, pi. iii, lib, c, 12. 

 1895. Helopora Harrisii. Whiteaves, Pal. Foss., Ill, Part II, p. 117. 



1897. Helopora Harrisi. Simpson, Fourteenth Ann. Rep. State Geologist New 

 York for the year 1894, figs. 113-115 (p. 548). 

 Cincinnati (Richmond): Waynesville, Blanchester, and other localities in 

 Ohio; Stony Mountain, Manitoba. 



Helopora imbricata Ulrich. 



1890. Helopora imbricata. Ulrich, Geol. Sur. Illinois, VIII, \). 644, pi. xxix, 5. 

 Cincinnati (Richmond): Wilmington, Illinois. 



Obs. This form may be the tertiary segments of Arthroclema angulare 

 Ulrich. 



Helopora ?? irregularis Billings, 



1866. Helopora irregularis. Billings, Catal. Sil. Foss. Anticosti, p. 39. 

 Anticosti: Anticosti Island. 



Helopora lineata Billings. See Nematopora lineata (Billings). 

 Helopora lineopora Billings. See Nematopora ? lineopora (Billings), 



Helopora ?? meeki James, 



1878. Helopora meeki. James, Paleontologist, No. 1, p. 3. 

 Cincinnati: Warren County, Ohio. 



Obs. This is in all probability the same as Dicranopora internodia (Mil- 

 ler and Dyer), but the description given is too meager to determine the 

 question. 



Helopora mucronata Ulrich. 



1890. Helopora mucronata. Ulrich, Jour. Cincinnati Soc. Nat. Hist., XII, p. 



192, fig. 16e. 

 1893. Helopora mucronata. Ulrich, Geol. Minnesota, III, p. 193, i)l. iii, 10. 

 Trenton: Cannon Falls and St. Paul, Minnesota. 



Helopora nodosa Billings. 



1866. Helopora nodosa. Billings, Catal. Sil. Foss. Anticosti, p. 38. 

 Anticosti: Anticosti Island. 

 Helopora parvula James. See Bythopora parvula (Jame.s). 



