PLATE LXVI— Contlnoed. 



CoNCHiDiuM Gkeenii, sp. nov. 



Piga. 30-23. Profile, cardinal and ventral views of a 8i)ecimen somewhat restored about the margins ; 

 showing the short, ventricose valves and fine, duplicate plication. 

 Niagara dolomites. Near Mihoaukee, Wisconsin. 



CoNCHIDIUM, sp. 



Kg. 38. An internal cast of the pedicle-valve of a probably undescribed species j shovring the character 

 of the plication and the length of the median septum. 

 Niagara dolomities. Hawthorne, Illinois. 



CONOHIDIUM CRASSIPLICA, Sp. IIOV. 



Figs. 34, 26. Dorsal and j>rotile views ; showing the ovate form of the shell, the subequally convex valves, 

 short and depressed beak of the pedicle- valve and the coarse, duplicate plication of the 

 snrfkce. 



Niagara group. Probably frmn the xAcinity of Louisville, Kentucky. 



