Cr 
DEVONIAN FAUNAS. oe) 
upper part of the last volution rounded, becoming angular and _pli- 
cate below; aperture somewhat rounded; peristome sinuous. Surface 
marked by fine, undulating, transverse strizw, which are crossed by 
much finer, obscure or obsolete, longitudinal striew.”—Hall. 
Remarks.—This type of gasteropod shell is not common in the 
Coeymans limestone fauna, most of the specimens observed being 
from the upper beds near Hainesville. Those which are well enough 
preserved for identification seem to agree most closely with Hall’s 
figures and description of P. gibbosum, and are consequently so 
named. 
TENTACULITES ELONGATUS Hall. 
Plate XXXII., Fig. 4. 
See, also, pp. 319 and 363. 
Fragments of this species are occasionally present in the Coeymans 
limestone fauna. They are usually in the form of internal casts, but 
the surface of the shells may occasionally be observed. The casts have 
the appearance of being a series of truncated cones placed end to end, 
each one being slightly smaller than the preceeding one, and forming 
a series of annulations, of which the lower slope is perpendicular and 
the upper one very gradual. Externally the annulations are rounded, 
the entire outer surface of the shell being marked by fine, annular 
strie. 
ARTHROPODA. 
TRILOBITA. 
DALMANITES PLEUROPTYX (Green). 
Plate XXNAIL., Wig. 1: © 
t 
1859. Dalmania pleuroptyx Hall, Pal. N. Y., vol. IIf., p. 356, pl. 
WA, figs. 1-12, pl. 75, fig. 1. 
Description.—*Pygidium triangular, transversely convex; the pos- 
terior extremity acute, attenuate; the axis a little depressed toward 
the lower extremity, which rises in strong relief above the border 
