FOSSILS OF THE CARBONIFEROUS. 263 
Genus ZAPTYCHIUS, n. g. 
Shell minute, elongate; aperture large, oblong nearly vertical; outer 
lip thin, columellar lip reflected, plicated. 
Surface of shell marked by slightly oblique longitudinal striz. 
Type: Zaptychius carbonaria. 
Zaptychius appears to have its nearest living ally in Auricula, although 
differing in the form of the body volution and spire from the typical forms 
of that genus; the presence ot the Auricula-like aperture and clongate shell, 
vertically striated, afford the basis for a new generic description. 
Zaptychius carbonaria Walcott. 
Zaptychius carbonaria Walcott, 1883. - Science, vol. ii, p. 808, fig. 1. 
Shell small, slender, the body volution having a length of about 6.5™", 
and a greater diameter of 2.5"; aperture rather large, elon- 
gate, narrow posteriorly and broadly reunded in front; col- 
umellar lip thickened anteriorly, the thickened portion cury- 
ing inward opposite the umbilical chink to form a rounded 
plication or ridge on the lip, which is reflected back on the 
volution and marked by a second tooth-like plication pro- 
jecting a short distance out into the aperture a little posterior 
to the first. The number of volutions is unknown. 
Surface of the shell marked by even, equidistant, nearly 
vertical strize that distinctly define the interspaces between 
them. 
The form of the spire above the portion of the volution 
preceding the body volution is unknown, although from the ey Bare 
character of that preserved and the presence of a trace of a volution 3.5™ 
above the body volution, it was probably more or less slender and elongate. 
Formation and locality—Lower portion of the Carboniferous formation, 
in a chocolate-colored limestone, associated with Physa prisca and Ampulla- 
ria ? Powelli, Eureka District, Nevada. 
