NIAGARA LIMESTONE OF CHICAGO, ILLINOIS. 



83 



Geographical Distribution of Niagara Species identified at Chicago. 



Petraia calicula Hall sp 



Zaphrentis turbinatus Hall sp 



Diphyphyllum ca;spitosuin Hall sp. 

 Favosites gothlandica Lam 



" venustus Hall sp 



Cladopora fibrosa Hall 



" seriata Hall 



" reticulata Hall 



Halysites catenularia Linn. sp. . . . 



Stictopora punctipora Hall 



Polypora incepta Hall 



Fenestella elegans Hall 



Lichenalia concentrica Hall 



Eucalyptocrinus oniatus Hall 



Glyptocrinus Carleyi Hall 



Caryocrinus ornatus Say 



Caryocystites cylindricus Hall 

 Strophomena rbomboidalis Wahl. . . 

 Atrypa reticularis Linn, sp 



" nodostriata Hall 



Meristella nitida Hall sp 



Spirifera crispa Sowb 



" radiata Sowb. 



Ehynchonella neglecta Hall 



* Pterinea neglecta McChesney sp. 



Ambonychia mytiloidea Hall 



Pleurotomaria Halei Hall 



Hoyi Hall 



Loxonema subulata Con , 



* Orllioceras Laphami McChenesy. 

 Cyrtoceras Fosteri Hall 



N. Y. 



Wis. 



I.M). 



Can. 



Eur. 



Enumeration of Species. 



Petraia calicula Hall sp., Pal. N. Y., ii. p. Ill, pi. xxxii. fig. 1, a-k. 



Zaphrentis turbinatus Hall sp., Pal. N. Y., ii. p. 112, pi. xxxii. fig. 2. 



Cystiplvjllum sp ? A fragment generically well marked. 



Diphyphyllum cccspitoswn Hall sp., Pal. N. Y., ii. p. 116, pi. xxxiii. fig. \, a-h. 



Favosites gothlandica Lam. (F. niagarensis Hall.) We adopt the suggestion of Billings 

 (Canad. Journal, March, 1859, p. 99), in referring this form back to the original species. It 

 occurs abundantly in the upper part of the quarry. 



Favosites venustus? Hall sp., Pal. N. Y., ii. p. 120, pi. xxxiv. fig. 1, a -i. 



The agreement is not striking. This is an expanded, incrusting coral, adapting itself to 

 the inequalities of the underlying surface, and, in places, developing tubercular masses. 

 The tubes are ordinarily not more than an eighth of an inch long, but, in the tubercles 

 become sometimes half an inch in length. In the tuberculous parts, the diaphragms are 

 seen to be direct and crowded. No indications of a radial system are seen. The cell- 

 mouths are conformable to this species. The Chicago fossil bears considerable resemblance 

 to Thecostegites hemisphecricus Rom. (Sil. Fauna des Westl. Tenn. Taf. ii. fig. 3). 



* These species are not enumerated by Hall among the fossils of Wisconsin. 



