CORALS AND BRYOZOA. 253 



parallel, scarcely expanding before bifurcating ; transverse section lenticular, 

 sub-angular at the middle, somewhat abruptly contracting near the margins ; 

 angles very acute ; non-celluliferous marginal space about .33 mm. in width ; 

 bifurcations occurring at intervals of from 5 to 7 mm. on the speci- 

 mens observed ; branches diverging at an angle of about forty-five degrees. 

 Cells tubular, for part of their length recumbent, then abruptly curving 

 and opening directly outward. Intercellular space occupied by irregularly 

 disposed vesicles. Cell apertures circular or very broadly oval, pustuliform ; 

 disposed in nearly parallel longitudinal rows, and separated by two or three 

 times the diameter of an aperture ; at the center of the branch they have a 

 diameter of about .15 mm., those of the marginal rows are larger, having a 

 diameter of about .22 mm.; diameter of the pustules .25 mm., increasing to 

 .35 mm. Peristomes thin, very slightly elevated. Ranges of apertures 

 separated by prominent, rounded ridges, having a width equal to or greater 

 than the diameter of an aperture, and elevated equally with the pustules. 



Formation and locality. Hamilton group, four miles south of Le Roy, Genesee 



county, N. Y. 



Stictopora recta, n. sp. 



NOT KIGURKD. 



ZoARiUM consisting of a flattened dichotomously branched frond. Branches 

 from 1 to 1.25 mm. in width, margins parallel, the branches not expanding 

 before bifurcating ; transverse section lenticular, abruptly contracting near 

 the margins, greatest thickness .33 mm. ; non-celluliferous space at the mar- 

 gin very narrow or ob.solete ; bifurcations comparatively distant, occurring 

 at intervals of about 6 mm. on the specimens observed ; branches diverging 

 at an angle of forty-five degrees. Cells tubular, arising very obliquely from 

 the mesotheca, abruptly curving and opening directly outward. Intercellular 

 tissue vesiculose, vesicles irregularly disposed. Cell apertures oval, length 

 about .18 mm., or slightly less, width a little more than one-half the length; 

 regularly dispo.sed in parallel longitudinal rows, separated by less than the 



