Lower Helderbero Brtozoa and Corals. 101 



In general appearance this species closely resembles C, elegantula 

 of the Niagara group ; but the cells are smaller and much more dis- 

 tant, while tlie cell margins of C. elegantula ?iVQ never elevated ; also 

 the intermediate pits are larger and more distinct. It resembles in 

 some degree C.perelegans^ but the cells are less circular, the margins 

 more strongly elevated, and the intercellular pits less distinct. 



Formation and locality. — In the shaly limestones of the Lower 

 Helderberg group, at Schoharie, New York. 



Callopora macropora n. sp. 

 Bryozoum forming slender, solid branches, with distant, widely 

 diverging bifurcations ; the branches seldom wider than a twentieth 

 of an inch. Surface marked by comparatively large, elongate-oval 

 or slightly angular cells. Intercellular spaces narrow, often only a 

 narrow ridge, intercellular pits few, small and angular, never more 

 than a single series so far as observed, and no spines have been seen 

 on the cell margins. 



This is a very distinct and well marked species, characterized by 

 the large cells and slender branches. A single branch, apparently 

 belonging to the same species, has been found in the Niagara group 

 at Lockport. 



Formation and locality. — In the shaly limestones of the Lower 

 Helderberg group, at Catskill creek, Greene county ; near Clarksville, 

 Albany county, and at Schoharie, New York. 



Callopora venusta n. sp. 



Bryozoum consisting of hollow branches, usually occurring flattened 

 upon tlie surface of slabs ; varying in width from a sixteenth to more 

 than a fourth of an inch ; their surfaces often nodose or tortuous. 

 Inner surface of the tubes longitudinally striate and marked by 

 strong concentric wrinkles. Cells small, longitudinally elliptical, not 

 contiguous, their margins not distinctly elevated, though showing in 

 some instances a well defined border. In well preserved speci- 

 mens the cell margins are marked by short, obtuse spines, generally 

 situated one on each side at the point of greatest diameter ; occasion- 

 ally there is also one at the upper or lower side. Intercellular spaces 

 marked by one or more series of angular depressions or pits, which 

 are sometimes almost as large as the true cells. 



This species has much the general aspect of C. elegantula of the 

 Niagara group, but the cells are much smaller, elongate instead of 

 circular, and in the whole appearance is of a finer texture. 



