214 
PALAEONTOLOGY OF NEW YORK. 
Formations and localities. In the Marcellas shale at Schoharie, and Bridge- 
water, N. Y., and in the lower part of the Hamilton group near Unadilla 
Forks, and at Cherry Valley, N. Y. 
CONULARIA CONGREGATA. 
PLATE XXXIV, FIG. 1 ; AND PLATE XXXIV A, FIG^. 9, 10, 11. 
Conularia congregata, Hall. Illustrations of Devonian Fossils : Pteropoda, plate 28, fig'. 1. 1876. 
Form regularly pyramidal, with the sides somewhat rapidly expanding. Trans¬ 
verse section quadrangular, with the sides equal. Faces of the pyramid 
equal, having apparently been nearly or quite plane, usually not marked 
by a median furrow, or such furrow but faintly indicated. Angles marked 
by a narrow, abrupt furrow, into which the strife of the surface are 
continued. Aperture of the shell unknown. Summit broadly truncated, 
apparently by a thin septum. 
Surface marked with fine, elevated striae, which are regularly and closely 
tuberculated along their crests, separated from each other by interspaces 
two or three times their width in the upper part of the shell, and in the 
lower part by interspaces equal to their width; striae distinctly and 
rather deeply curved towards the aperture of the shell; interspaces, in 
well preserved specimens, distinctly striate across their width, a feature 
probably not structural, but probably due to a wrinkling of the shell 
under pressure; all the ornamentation uninterrupted in crossing the 
median line, being continued quite into the depression of the narrow 
grooves of the angles. 
The surface-markings, as given above, are from impressions of the thin and 
but partially preserved test, which has been left in the soft shale in which the 
fossil is imbedded. As the shell increases in age, the spaces between the 
transverse striae diminish, not always gradually, but frequently by a sudden 
crowding together. Such bands of finer striae occur in all parts of the shell; 
following which, the surface again resumes its original character, except on 
