TRILOBITES. 709 
Oyphaspis galenensis.] 
Genus CYPHASPIS, Burmeister, 1843. 
CYPHASPIS ? GALENENSIS, ”. Sp. 
This name is applied to a single minute cranidium bearing an ellipsoidal, very 
convex glabella surrounded by deep dorsal furrows and tapering about equally 
toward both extremities; and with narrow convex fixed cheeks. All evidence of the 
lobation of-the glabella is very obscure, indeed consisting only of a slight lateral 
indentation on one side, at about the middle of its length, and of three equidistant 
elevated lines on the other. The surface is smooth or very faintly granulose on the 
glabella and more coarsely papillate on the cheeks. 
Fig. 82.—Cranidium of Cyphaspis? galenensis. (x 5). 
The fossil evidently represents an undescribed species and may therefore take 
the name here proposed, but its generic relations remain quite uncertain. In 
general appearance, form of glabella, convexity of cheeks and curve of facial 
sutures, it is like Cyphaspis, but it altogether lacks the basal glabellar lobes of that 
genus. 
Two other species from the Lower Silurian faunas of America have been referred 
to Cyphaspis: C. girardeauensis Shumard,* a normal representative from the Trenton 
horizon, and C.? brevimarginata Walcott,; from the Pogonip group of Nevada, a 
form having characters not unlike those of C.? galenensis. 
* Geol. Rept. Missouri, p. 197, pl. vim, fig. 11, 1855. 
+ Palwont. Eureka District of Nevada, p. 93, pl. x11, fig. 10, 1884. 
Formation and locality.—The Minnesota specimen is from the Galena shales at Cannon Falls. 
