Plate 3 



Eriptychiida gen. and sp. indet. 1-4, USNM 21342, a detaclied keel-like plate, presum- 

 ably belonging to a new genus of the Eriptychiida, from the same core and the same depth 

 as the Pycnaspis specimen shown in figures 1-3 of plate 2: 1, external view; 2, 3, lateral 

 views from opposite sides; 4, basal view. 5, 6, USNM 21818, a detached ridge-scale, some- 

 what incomplete, from the same layer and locality as the holotype of Pycnaspis splendens, 

 new genus, new species: 5, external view; 6, anterior view. Magnification: 1-4, X 7; 

 5, 6, X 6.5. 



