PTEROPODA. 211 



The length of one specimen, imperfect at both extremities, is about ninety 

 millimetres; the other, incomplete at the apex, is about eighty millimetres 

 long ; the shortest diameter at the base is about twenty millimetres, and the 

 longest about thirty millimetres. 



Formation and localities. In the soft calcareous shales of the Hamilton group 

 of New York, in the Genesee y alley near Moscow, and in the coarser shales of 

 the group at Morrisville in Madison county. 



Conularia Cayuga. 



PLATE XXXIV, FIGS. 2,5. 

 aria Cayuga, Hall. Illustrations of Devonian Fossils : Pteropoda. plate 28, figs. 2, 3. 1876. 



Form elongate-pyramidal, the adjacent faces apparently equal, and gradually 

 expanding from the apex. The transverse section unknown, as also the 

 form of the aperture. Faces of the pyramid apparently a little convex, 

 with a shallow, depressed, median line, and strongly marked furrows at 

 the angles. The summit is truncated. 



Surface marked by moderately strong, sharply elevated striae, with interspaces 

 about three or four times as wide in the earlier growth of the shell, and 

 becoming much narrower towards the base of the pyramid; the striae 

 minutely tuberculose on their crests, and the interspaces striate; the 

 direction of these striae sometimes nearly vertical, but usually oblique, 

 and in some parts distinctly diverging from the median line. 



The surface characters, as given above, are drawn from a gutta-percha 

 impression, taken from a mould of the exterior, from which the shell had, for 

 the most part, been dissolved and removed, but with small portions remaining, 

 which show the internal surface. 



This species, in its general form, is not dissimilar to C. undulata, but the 

 strirc are stronger, and the interspaces between them are much greater, 

 especially in the upper part of the shell, while towards the aperture these 

 spaces are very narrow, and the striae much crowded. The presence of striae 

 crossing the interspaces is a distinctive feature; but these are not visible in all 



