244 New Species of Fossils from Ohio. 



S. zic-zac, Hall. 

 Leiorhynchus, Hall. 



L. limitaris, Vaiiuxem. 

 LA MEL LIBRA NO II I A TA . 



AVICULOPECTEN, McCoj. 



A. eijnilaiera, Hall. 

 Pterinea, Goldfuss. 



P. similis, Wliitf. 

 Autinodesma, Sandberger. 



A. suhrecta, Wliitf. 

 Grammysia, De Verii. 



G. Ms'ulcata, Conrad. 

 Nyassa, H. and W. 



N. argiita, H. and W. 



[NOTE TO PAGE 316.] 



Genus N1'A§SA, H. and W. 



Nyassa, H. & W., Prelim. Notice of the Lamellibranchiate Shells of the 

 Upper Helderberg, Hamilton and Chemung Groups, &c. Albany, Dec, 

 1869, p. 28, 



Shells bivalve, very oblique and transversely ovate in form. Posterior 

 hinge-plate narrow, bearing from one to four long slender ridge-like teeth. 

 Anterior plate broad, marked by numerous small i^oint-like teeth with in- 

 termediate depressions, arranged somewhat radiating from the middle of 

 its inner border. Adductor muscles two, one at each extremity. Pallial 

 line entire. Ligament internal. Type, -/"V. arguta. Name, mythological. 

 Geological range, so far as known, Devonian. Family relations apparently 

 near Megalomus, Hall, and Megalodon, Sowerby. 



