New Species of PALyEozoic Fossils. 199 



^ Trematospira hirsuta Hall. 



^ Nucleospira concinna Hall. 



f Athyris spiriferoides Eaton. 



JC Athyris vittata Hall. 



•f Meristella nasuta Conrad. ^rUr^dal^a xadxa.h -JP^^^ 



K Meristella (Pentagonia) unisulcata Conrad. 



/. A try pa reticularis"^ Linnmus. 



}C Atrypa aspera Schlotheim. 



y. Rhynchonella (Stenocisma) tethys Billings. 



^ Pentamerella arata Conrad. 



/ Terebratnla harmonia JIall. 



/ Cryptonella lens Hall. 



/ Cryptonella rectirostra. 



Lamellibranchiata. 



/ Pterin ea flabellum Conrad. 



This species occurs in the upper limestone of the Falls of the Ohio, 

 and elsewhere in that neighborhood, as well as in limestone of the 

 same age in the State of Ohio. It presents a great variety of aspect 

 in its gradation from the young to the mature and older condition of 

 the shell, in which it might readily be mistaken for different species. 

 In the examination of several hundred specimens from the rocks of 

 ISfew York and the west, this species has been found to range from the 

 upper limestone of Ohio through the Hamilton and Chemung groups 

 of New York, and to present such extreme varieties that one plate 

 in the Palaeontology of New York, Yol. Y, has been found insufficient 

 for the illustration of its exterior forms and internal structure. 



)C Limoptera cancellata : var. occidens H. (& W. 

 )C Aviculopecten pecteniformis ConroA. 

 / Aviculopecten princeps Conrad, ' 



/ Aviculopecten parilis Conrad. 



Forms referable to these three species of Conrad occur in the 

 upper limestone of the Falls of the Ohio, and in that neighborhood, as 

 well as in the same limestone in Indiana and Oliio, and also in the 

 Hamilton group of New York. On examination of a large number 

 of specimens, it appears probable that the three species mentioned 

 above may all be included under one term. 



/ Nuculites triquetra Conrad. 



>c Modiote (Modiomorpha) concentrica Hall. 



X Grammysia (Leptodomus) as cuAdiL: w ota :. gibbosa //. ds W. 



* The variety referred to A. 2nisca, Pal, N. Y., vol. IV, page 324, foot note, may for convenience o 

 reference be designated as var. nuntia, 1. c, pi. 51, figs. 10-24; while it will be convenient to dcsig 

 nate the gibbous form, plate 52, figs. 4-6, as A. reticularis var. mntricosa. 



