256 PALEONTOLOGY OF NEW YORK. 



Stictopora lobata, n. sp. 



NOT FIODBBD. 



ZoARiUM consisting of a flattened, dichotomously branched frond, proceeding 

 from a spreading base, which is attached to foreign objects. Branches from 

 2 to 2.50 mm. in width, margins sub-parallel, the branches slightly expand- 

 ing before bifurcating ; non-celluliferous margincal space narrow, width a 

 little more than .25 mm. ; transverse section lenticular, greatest thickness 

 .75 mm. ; on the margins of the branches, at intervals of a little more than 

 1 mm., are lobes or projections, extending beyond the margin about .75 mm., 

 and having a width of about 2 mm.; they have the appearance of aborted 

 lateral branches ; the cell apertures upon them extend entirely to the 

 margin ; bifurcations comparatively infrequent, occurring at intervals of 

 8 mm. or more on the specimens observed. Cells tubular, recumbent for 

 the greater portion of their length, then abruptly turning and opening 

 directly outward. Intercellular tissue consisting of irregularly disposed 

 vesicles. Cell apertures oval, length about .20 mm., width from one-half to 

 two-thirds the length, disposed in longitudinal, nearly parallel rows, about 

 six rows on each face of the branch ; apertures of the rows separated 

 by less than their length ; the apertures on the lobes are larger and less 

 regularly disposed. Peristomes strong, posterior portion a little the more 

 elevated, smooth, not denticulated. Ranges of apertures separated by prom- 

 inent, narrow, nodose ridges, which have a width of about two-thirds that 

 of the apertures ; nodes small, regularly disposed, about equal in number to 

 the cell apertui'es. 



In its manner of growth this species most nearly resembles S. palmipes, but 

 the lobes are never prolonged into lateral branches, the frond is more rigid in 

 appearance, the margins more nearly parallel, and the frond is without the 

 thin, wide, non-celluliferous marginal space characteristic of that species ; from 

 other species it may be distinguished by its marginal lobes. 



Formation and locality. Reed's Corners, near Canandaigua lake, Ontario 

 county, N. Y. 



