CORALS AND BRYOZOA. 97 



INTRAPORA, Hall. 1881. 

 Intrapoka puteolata. 



PLATE XXIX, FIGS. 18-26. 



Tntrapora puteolata. Halt,. Trans. Albany Institute, voL x, abstract, p. 16. 18S1. 



" " " Report of State Geologist for 1885, advance sheets. Expl. pi. 29, figs. 18-26. 



1886. 

 Compare SticUrpordla interstincta, Ulrich. Journal Cin. See. Nat. Hist., vol. v, No. 3, p. 169. PI. 8, figs. 



9, 9a. 1885. 



ZoARiUM consisting of a flattened, dichotomously bifurcating or branching frond, 

 arising from a spreading base ; width of branches usually from 2 to 4 mm., 

 but sometimes 20 mm. or more ; greatest thickness 1 mm. Cells tubular, 

 for one-half their length essentially parallel with the mesotheca, then turn- 

 ing abruptly outward. Cell apertures oval, length a little more than .25 mm., 

 width three-fourths the length ; very closely and irregularly disposed, fre- 

 quently in contact. Peristomes strong, slightly and equally elevated. Inter- 

 apertural space occupied by minute angular pits, generally a single series 

 between adjacent apertures On the non-celluliferous margin of the branch 

 these pits are so disposed that their margins have the appearance of oblique 

 striations. Intercellular space irregularly vesiculose. 



The surface of the broader forms of this species is very similar to that of 

 Fistulipora intercdlaia. 



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



PRISMOPORA, Hall. 1881. 

 Prismopora triquetra. 



PLATE XXVUI, FIGS. 8-10 ; and PLATE XXIX, FIGS. 9-15. 



Prismopora triqvetra, Hall. Trans. Albany Institute, vol. x, abstract, p. 17. 1881. 1883. 



lU^port of State Geologist for 1882. Expl. pi. 25, figs. 8-10. 

 " " " Report of State Geologist for 1885, advance sheets. Expl. pi. 29, figs. 9-15. 



1886. 



ZoARiUM consisting of an irregular group of triangular branches, usually dichoto- 

 mously bifurcating, sometimes trifurcating. Faces of the branch equal, 

 width from 3 to 6 mm., concave, the concavity sub-angular along the middle, 

 a comparatively wide space at the margin destitute of cell apertures ; greatest 



