252 PALEONTOLOGY OF NEW YORK. 



Stictopora crenulata. 



PLATE LX, FIG. 22. 

 /Stictopora crenulata. Hall. Report of State Geologist for 1883, p. 44. 1884. 



ZoARiUM consisting of a flattened, frequently sinuous, dichotomously branched 

 frond, arising from a base composed of several rootlets attached to foreign 

 bodies ; the frond for a little more than 1 mm above the base is sub- 

 elliptical in section, striated, non-celluliferous, then becoming flattened. 

 Branches about 1.50 mm. wide; non-celluliferous marginal space very 

 narrow, width .25 mm.; margins essentially parallel, frequently crenulated, 

 the branches scarcely expanding before bifurcation ; transverse section len- 

 ticular, abruptly contracting near the margin, the angles very acute, the 

 remaining portion regularly convex ; bifurcations comparatively distant ; 

 branches widely diverging. Intercellular tissue consisting of irregularly 

 disposed vesicles. Cell apertures a little oblique, circular, diameter about 

 .18 mm., arranged in parallel longitudinal rows, separated by about twice 

 the diameter of an aperture, usually five or six rows on a branch ; the 

 apertures of the marginal rows are larger than the others and more oblique, 

 the upper portion of the cell walls frequently being exposed for a distance 

 equal to twice the diameter of an aperture. In the central ranges there 

 are fifteen apertures in the space of 5 mm., in the outer ranges nine or ten 

 in the same space ; opposite each of these cells the margin is extended, 

 giving to it a crenulated appe.arance. Peristomes thin, nearly equally 

 elevated, the posterior portion being slightly the more prominent. Space 

 between the ranges of apertures flat or slightly convex, striated, generally 



three thin, angular striations between adjacent rows of apertures. 



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Formation and locality. Hamilton group, near Alden, Erie county, N. Y. 



Stictopora angularis, n. sp. 



PLATE LXI, FIG. M. 



ZoARiUM consisting of a flattened dichotomously branched frond, arising from a 

 spreading base. Branches from 2 to 2.50 mm. in width : margins essentially 



