214 PALEONTOLOGY OF NEW YORK. 



Formations and localities. In the Marcellus shale at Schoharie, and Bridge- 

 ^ ater, 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, FIGS. 9, 10, 11. 



Ctmularia congregate. 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 striae 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 bcinds of finer striae occur in all parts of the shell; 

 following which, the surface again resumes its original character, except on 



