DEVONIAN FAUNAS. 29 
G32 
times not at all, perceptible on the posterior wing, except along its 
upper margin, while they are not seen on the anterior wing), con- 
centrically marked by fine, lamellose strie, which, in the more per- 
fectly-preserved surfaces, are elevated and subimbricating; these 
striz are usually conspicuous on both the anterior and posterior wings. 
Surface of the right valve marked by broader and scarcely elevated 
radii and less-defined concentric striz.”—Hall. 
Remarks.—Fragments of a winged pelecypod shell are occasionally 
found in the Coeymans limestone, which are apparently to be identi- 
fied with this species. No specimens perfect enough for description 
have been observed, so that the above description has been copied from 
the New York Paleontology. 
CONOCARDIUM sp. undet. 
Plate XXXI., Figs. 19-20. 
Representatives of the genus Conocardium are rare in the Helder- 
bergian faunas. A single specimen from the Coeymans limestone 
near Peter’s Valley is too fragmentary for identification or description, 
but when complete it must have been a shell 15 mm. in height by 18 
mm. in length. It is marked by flat ribs about equal in width to the 
flat-bottomed grooves which separate them. 
GASTROPODA. 
BULIMORPHA ? HELDERBERGIAE DN. sp. 
Plate XXXII., Fig. 8. 
Description.—Shell small, with five or six volutions, apical angle 
about 45°, the apex obtuse. Surface of the volutions depressed-con- 
vex, the suture shallow. Aperture subovate in outline, outer lip entire, 
columella lip smooth. Surface nearly smooth, with very fine lines 
of growth, which can only be detected with the aid of a lens. 
The dimensions of a nearly-perfect specimen are: length, 7.5 mm.; 
diameter of last volution, 4.5 mm.; height of aperture, 4.5 mm. 
