204 C. SCIIUCITERT — LOWER HELDERBERG-ORISKANY FORMATIONS 



The succeeding list of specific equivalents for Bohemia and the Lower 

 Helderberg of New York was not prepared to fit the case in hand, but is 

 the outcome of an examination of Barrande's fine plates. The writer 

 lias often collected in the Lower Helderberg and Oriskany, and has 

 studied their faunas for ten years. In going over Barrande's plates he 

 was surprised to find that the brachiopods in the two regions were very 

 similar. A careful perusal of the list here given will show that the most 

 important Lower Helderberg brachiopods have direct equivalents in the 

 Konieprussian. Each region has, of course, its own development, and 

 the common forms of one region may be rare in the other. For instance, 

 in America the great development of the subgenera of Orthis — Dalma- 

 nella and Rhipidomella — have but little diversity in etage F 2 , while here 

 the spire-bearing families Meristellidrc and Athyridse have a far greater 

 diversity. The same is also true for the Rhynchonellida^, although these 

 shells are varied and abundant in the Lower Helderberg. These are the 

 local aspects of widely separated faunas, however, and when such sim- 

 ilarities are detected as are indicated in the following list, the} 7 should 

 be given their full value : 



Bohemia, etage F 2 . 



Distinct radians Barrande. 



Orthis palllata B. (PI. 58). 



Ortlds pinguissina B. 



OrtJiis jinccursor B. 



Strophomena rhomboidalis (Wilckens). 



Strophomena bohemica. B. 



Strophomena. phillipsi B. 



Strophomena sowerbyi B. 



Strophomena sesopea B. 



Clionetes venuslus B. 



Chonetes inconslans B. 



Chonetes squamatulus B. 



Peutamerus sieberi v. Buch. 



Pentamerus opiatus B. 



Pentamerus firmus B. 



Rhynchonella eucharis B. 



Atrypa assula B. 



Rhynchonella phoenix B. 



Spirifer nerd B. Fj, F 2 . 



Qyrtina heteroclita Defrance. 



Atrypa reticularis Linne\ 



Atrypa semiorbis B. 



Merista lierculea B. 



Merista minuscula B. 



Atrypa compressa B. 



Atrypa inelegans B. 



Lower Helderberg. 



Orbicidoidea discus Hall. 



0. {Dalmanella) perelegans Hall. 



0. (D.) quadrans (Hall). 



0. (Scliizophoria) muUistriata Hall. 



Leptxna rh om boidalis. 



Strophonella punchdifera (Conrad). 



Stropheodonta varistriaia arata Hall. 



Stropheodonta, becld Hall. 



Orlhollieies deformis Hall. 



Chonostrophia helderbergix H. & C. 



[ Anoplia nucleata Hall. 



> Gypidula galeala (Dal man). 



? Anastrophia verneuili (Hall). 

 Eaton ia medialis (Vanuxem). 

 Eatonia peculiaris (Conrad). 

 Rhynchonella semiplicata Conrad. 

 Spirifer concinnns Hall. 

 Cyrtina dalmani (Hall). 

 Same species and local development. 

 Atrypina imbricata Hall. 



\ Merista typus Hall. 



Mi ristella bell a Hall. 

 Niicleospira ventricosa Hall. 



