FOSSILS OF THE CARBONIFEROUS. 249 
nearly transverse along the center, curving up rather abruptly anteriorly, 
and more gently at the posterior end; posterior line abruptly rounded at 
the point of greatest extension on a line with the center of the shell, above 
which it curves forward to the straight cardinal line. Valves marked by 
several distinct, but not prominent, ridges on the postero-cardinal slope. 
Surface ornamented by fine concentric strize, and a few obscure lines 
of growth. 
Formation and locality—lLower horizon of the Carboniferous Group, 
eastern slope of a small conical hill on east side of Secret-cation-road 
Canon, Eureka District, Nevada. 
Sanguinolites ? Nezenia, n. sp. 
Plate xix, fig. 9. 
Shell small, transversely elongate, the height being one-half the length; 
beaks small, depressed, and situated on the anterior third; anterior end nar- 
row, somewhat elongate and so abruptly rounded as to be almost angular; 
basal line slightly sinuate midway and curving up at each end; posterior 
end broadly rounded; cardinal line nearly straight The general surface 
of the valves is moderately convex, with a slight. umbonal ridge extending 
from the beak to the postero-basal curve, and also a rather broad, shallow 
mesial depression. 
Surface marked by several well-defined, concentric undulations of 
growth. 
Formation and locality—Lower horizon of the Carboniferous Group, 
eastern slope of a small conical hill on east side of Secret-canon-road 
Canon, Eureka District, Nevada. 
Sanguinolites striatus, n. sp. 
Plate xxili, fig. 7. 
Shell transversely elongate-oval, compressed convex, posterior umbonal 
slope angular. Cardinal line long, straight. Beak appressed, situated at 
about the anterior third. 
