228 



PALEONTOLOGY OF NEW YORK. 



The erroneous reference of this species has but, recently been corrected, in part, by Mr. 

 A. F. FoBRSTE, 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 0. calligramma, var. 

 flabdliies. While indisposed to continue a resupinate shell in this association, the necessity 

 of another name for the American species is evident. 



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

 Orthis callactis, Dalman, and that of Orthis pactinella, Emmons : 



ORTHIS, Dalman (as restricted). 



I. Group of Orthis callactis, Dalman. 



*0. costalis. Hall Chazy. 



* 0. orthambonites, Billings Quebec. 



* 0. Euryone, Billings Quebec. 



Billings Quebec. 



Conrad Trenton. 



Conrad Trenton and 



Hudson River 



* 0. Hippolyte, 



* 0. disparilis, 



* 0. tricenaria, 



* 0. Davidsoni, 



DE Verneuil Niagara. 



> 0. fiabellites, Hall. Niagara. 



D I N R T H I S . 



IV. (rroup of Orthis pectinella, Emmons. 



* 0. pectin ella, Emmons Trenton. 



* 0. pectinella, „ ti + 



var. semiovalis, JiALL IreutOn. 



* 0. Sweeneyi, N. H. Winchell, Trenton. 



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



The following tabular arrangement of the generic subdivisions of the 

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

 of the entire family : 



