30 Cincinnati Society of JSTatural History. 



Formation and Iocalit3' : not an nncommon fossil in the lower three 

 hundred feet of the Hudson River Group, as exposed at Cincinnati, O. 



Crateripora lineata, var. expansa, 



[^iy. —Eiapansa, expanded.] 



The specimens upon which this variety is established are attached to 

 an Endoceras, and form rather large expansions, the largest examined 

 covering the Endoceras for the distance of two and a half inches. The 

 cup-like depressions are from half an inch to an inch or more distant 

 from each other, over one line in diameter and about one half a line in 

 depth, with a secondary, very shallow depression surrounding them, 

 having a diameter of two lines. The canal apertures are arranged be- 

 tween raised lines, the same as in the typical examples of C. lineata, but 

 where the specimens are well pi-eserved the ridges are ornamented with 

 a row of small granules. 



This form may be distinct from C lineata, but the material at hand 

 is not sufficient for a satisfactory determination of that point. At any 

 rate it is an easil}' distinguished variety of that species. 



Formation and locality: in the middle part of the Hudson River 

 Group, at Hamilton, O. 



Collector: E. O. Ulrich. 



Crateripora erecta, n. sp. (Plate VII,, figs. 29, 29r?.) 



[Eiy. —Erecta, erect.] 



This species grows parasitically upon foreign substances (usually 

 upon Choitetes mammulatus), and consists of small, circular, or some- 

 what irregular bodies, having much of the form of the t3q3e, C. lineata. 

 excepting that the margin of the central depression is not raised. The 

 cup has a diameter equaling one seventh of that of the entire speci- 

 men. The upper surface is covered with the openings of minute canals, 

 of different sizes, irregular shapes and arrangement, apparentl}- pass- 

 ing with but little obliquity from the lower or attached portion, to the 

 upper surface. About fifteen canal apertures occup}' the space of one 

 line. Diameter of expansions from one to two and a half lines. 



This species is distinguished from either of the preceding forms b}' 

 its smaller size, comparatively smaller cup, its irregular arrangement 

 of the canals, and in having the latter more erect in their course from 

 the base to the upper surface. 



Formation and locality : the type specimens were found in the Hud- 

 son River Group, at Cincinnati, O., at an elevation of four hundred 

 feet above low water mark in the Ohio River. 



Collectors : H. E. Dickhaut, E. O. Ulrich. 



