Report of the State Geologist, 259 



The specimens at hand show considerable variation in form and 

 dimensions, though the surface characters are persistent throughout. 

 The best preserved and most robust of these, in which the aperture 

 is retained but the basal portion lost, has a length of 206 mm., and 

 a width across the aperture of 56 mm., greatest width, 69 mm. A 

 much more slender example measures 256 mm. in length and 38 mm. 

 in width. The tendency to curvature in growth is carried to an 

 extreme in a single specimen which has the form of an arc with a 

 radius of 65 mm. 



Formation and localities. — In the sandstones of the Chemung group 

 at Alfred, Friendship and Nile, Allegany county, N. Y. 



DiOTYOPHYTON VASCELLUM, Sp. n. 



The original specimen of this species is a large explanate fragment 

 indicating a broad, flattened cup, one of whose transverse diameters 

 is six times the other. The cup appears to have expanded rapidly 

 from the base upward, and in transverse section was probably 

 elongate-elliptical. 



Surface rather finely reticulate, the primary longitudinal and trans- 

 verse bands being numerous and the meshes made by them, square; 

 only a single series of secondary bands is observable. 



In addition to these bands is a series of very broad, obscure reticu- 

 lating ridges parallel to and crossed by the bands. These are much 

 more distinctly retained on the lower, slightly concave side of the 

 specimen, and appear to have been of purely ornamental character. 

 The normal width of the original is 150 mm. ; the length as far as 

 preserved 188 mm. 



Formation and locality. A loose, somewhat waterworn fragment from 

 the Chemung group; found at Alfred, Allegany county, N. T. 



DiCTYOPHYTON RaNDAXLI, Sp. U. 



Cup subcylindrical or gradually expanding. Reticulum composed 

 of cancellating acicular bands of nearly equal size. Surface crossed 

 by series 6f ridges parallel to the bands; these are of two sizes, the 

 larger making quadrate areas which are subdivided into four quad- 

 rules by the lesser series; these again are divided by the meshes of 

 the reticulum into sixteen smaller quadrules and each one of these 

 divided into four parts by the finest of the spicular bands. There 

 are, thus, in each of the squares into which the sui'face is divided 256 

 quadrules of the third degree. 



At the intersection of the primary and secondary surface ridges, a 

 low node is formed, the size of which depends on the value of the 

 intersecting ridges. The original specimen is entire at the aperture, 



