228 



PALEONTOLOGY OF NEW YORK. 



The en'oueous reference of this species has but. recently been corrected, iti part, by Mr. 

 A. F. FoERSTE, t who has pointed out some of the differences already mentioned, and has 

 proposed to retain the species (as it stands in the list) associated with O. caUigramma, var. 

 flabelliles. While indisposed to continue a resupinate shell in this association, tlie necessity 

 of another name for the American species is evident. 



The following arrangement will indicate the relations of Orthis flahelUtes to the group of 

 Orthis callactis, Dalman, and that of Orthis pectinella, Ennnons : 



ORTHIS, Dalman (as restricted). 

 I. Group of Orthis cALi-AfTis, Dalman. 



* 0. costalis. Hall Chazy. 



* O. orthambonites, Billings Quebec. 



* 0. Euryone, Billings Quebec. 



Billings Quebec. 



Conrad Trenton. 



Conrad Trenton and 



JIudson River 

 DE Yernedil Niaarara. 



* 0. Hippolyte, 



* 0. disparilis, 



* 0. tricenaria. 



* O. Davidsoni, 



D I N R T H I S . 



IV. Group of Orthis pectinella, Emmons. 



* O. pectinella, Emmons Trenton. 



* O. pectinella, 



var. semiov.ilis, Mall Trenton. 



* O. Sweeneyi, N. H. Winchkll, Trenton. 



» O. tiaViellites, Hall. Niagara. 



t Proceedings Boston Society Natural History, vol. xxiv. pp. 308-312. 1890. 



The following tabular arrangement of the generic subdivisions of the 

 Onrnm^ will show the geological range of each one of the subdivisions, and 

 of the entire family : 



