264 PALEONTOLOGY OF NEW YORK. 



With our present knowledge there may also be included in the same group, 

 the species described by Mebk, from the McKenzie river, as Rensselaria lavis* 

 and more recently identified by Whiteaves, in the same region, associated with 

 Stringocephalus Burtini, and other characteristic middle Devonian species ; and 

 also the interesting and abundant form discovered by Professor E. W. Claypole 

 in the sandstones of the age of the Hamilton group, in Perry county, Pennsyl- 

 vania,! subsequently described as Newberria Claypolii. This shell occurs in great 

 quantities both at the locality cited, and in a coarser pebbly sandstone at Pine 

 Grove, Schuylkill county, in the same State, a locality which has furnished most 

 instructive specimens of both the interior and exterior of the shell. 



There can be little reason to doubt that (Ehlert's Megalanteris inornata 

 (d'Orbigny sp.), to which reference has already been made, represents this 

 genus in the Devonian of western France. The agreement is found both in 

 the detailed structure of the hinge-plate, the arrangement of the muscular 

 areas and the character of the vascular sinuses. In default of other evidence, 

 it may be considered probable that the Atrypa Deshayesi, Caillaud, A. amygdala, 

 d'Orbigny, and Terebratula amygdalina, Goldfuss (Kayser), from the lower and 

 middle Devonian of France and Germany, also represent the genus Newbeeria. 

 This genus seems to be a later modification of the RENSSEL^ERiA-type of brachi- 

 opod structure. The true RENSSELiERiA, so far as known, closed its existence, in 

 America at least, with the disappearance of the fauna of the Oriskany sand- 

 stone. Amphigenia is not known in the faunas succeeding those of the Upper 

 Helderberg, while Newberria occurs in the lower and middle Devonian, Hamil- 

 ton group, and is probably not of earlier age. 



• Not Remselctria loevit, Hall, Pal. N. Y.. vol. Hi, p. 256. 1869. 



t See Proceedings of the American Philosophical Society, p. 236. 1883. 



