CORALS AND BRYOZOA. 103 



This species may be distinguished from G. sinuosa by its more slender form 

 and the absence of a carinae, and from G. tenuistriata by the much closer 

 arrangement of the lateral branches. 



Formation and locality. Upper Helderberg group, near Le Roy, Genessee 

 county, N. Y. 



CRISINELLA, Hall. 1883. 

 Crisinella scrobiculata. 



PLATE XXXni, FIGS. 6-8. 



Criainat scrobiculata. Hall. Trans. Albany Institute, vol. x, abstract, p. 20. 1881. 



CrUijuUa " " Report of Stete Geologist for 1882. Expl. pi. 26, figs. 6-8. 1883. 



ZoARiDM ramose, solid, celluliferous on one face, diameter 1 mm. ; transverse 

 section circular. Cell apertures circular, diameter 25 mm.; disposed in 

 oblique ascending rows from the center to the margins of the branch ; the 

 two series of rows alternating at the center. Space between the rows equal 

 to twice the diameter of an aperture. Peristomes strong, distinctly and 

 equally elevated. Interapertural space occupied by large polygonal pits. 

 Non-celluliferous foce of frond finely and irregularly striated. 



Formation and locality. Upper Helderberg group, Western New York. 



CYSTOPORA, Hall. 1881. 

 Cystopora geniculata. 



PLATE LXVI, FIGS. 7, 8. 

 Cystopora geniculata, Hall. Trans. Albany Institute, vol. x, abstract, p. 20. 1881. 



ZoARiUM consisting of a cylindrical aggregation of tubular cells ; length of cells 

 2 mm. ; width when first exposed .33 mm., increasing to .50 mm., then con- 

 tracting, having a diameter at the apertures of .28 mm. Cells alternating, 

 imbricating and forming spiral rows. 



Formation and locality. Upper Helderberg group. Falls of the Ohio river. 



