NO. 5 CAMBRIAN TRILOBITES 435 



Corynexochus bubaris Walcott — Continued. page 



2e. (X 2.) Pen and ink sketch of tive thoracic segments and pygi- 



dium. The original specimen has crumbled on the surface 



so that it cannot be photographed. U. S. National Museum, 



Catalogue No. 62742. 

 3/- (X4-) Hypostoma. U. S. National Museum, Catalogue No. 



62743- 

 The specimens represented by figs. 3, 2,a-g are from a leached 

 calcareous sandstone at locality 49, Lower Cambrian : near Emigs- 

 ville, York County, Pennsylvania. 



