Upper Helderherg Grovp, 



157 



Stictopora i^'vertis, n. sp. 



Bifurcations occurring at intervals of from eight to ten mm.; width 

 of branches, 2,5 mm., greatest thickness, 1.50 mm., width of non- 

 celluHferous marginal space, .85 mm. ; cells tubular, one mm. in 

 length, for one-half this length nearly parallel with the mesial-platu, 

 then turning abruptly, and opening directly outward; apertures cir- 

 cular, very frequently arranged in a V-shaped order across the branch ; 

 on the narrower portions of the branch they form oblique, arching, 

 transverse rows ; margins of apertures strongly and equally elevated. 



Locality — New York. 



Stictopora rhomboidea, n. sp. 



Bifurcations frequent ; branches widley diverging, width two mm., 

 greatest thickness one mm., edges obtuse ; cell apertures oval, length 

 .35 mm., disposed in irregular longitudinal rows, usually alternating, 

 margin thin, slightly elevated, granulose; between the apertures is a 

 thin sinuous granulose ridge, frequently touching the margins of the 

 cells ; in the transverse space between cells the ridges approach each 

 other frequently touching and coalescing. 



Locality — Xear Leroy, Genesee county, N. Y. 



Stictopora lixearis, w. sp. 



Ko bifurcations occur on fragments observed, though probably they 

 will be found in larger fragments; width of branch 1.50 mm., greatest 

 thickness. 50 mm.; cell-apertures circular, diameter. 20 mm., arranged 

 in longitudinal parallel rows, five or six rows on a stipe, 14 apertures 

 in the space of fivo mm., margins thin, slightly elevated, longitudinal 

 rows separated by comparatively strong angular ridges; non-cellulif- 

 erous margin very narrow or entirely wanting. 



Localities — Onondaga Valley and Leroy, Yo ' ' 



Stictopora perarcta, n. sp. 



Branches infrequent, diverging at an angle of 45°, width .90 mm., 

 greatest thickness .50 mm., non-celluliferous marginal space very nar- 

 row and frequently entirely wanting ; cell apertures, circular or broadly 

 oval, diameter .20 mm., arranged in longitudinal parallel rows, sepa- 

 rated by a comparatively strong rounded granulose ridge, margins of 

 apertures thin, slightly elevated, granulose. 



Locality — Onondaga valley, N. Y. 



INTRAPOKA, nov. yen. 



Bryozoum growing as in Stictopora ; stipe and branches broad, 

 bifurcating at somewhat regular intervals. Both sides celluliferous. 



