246 PALAEONTOLOGY OF NEW YORK. 



Stictopoba tumulosa. 



PLATE LXI, FIGS. 18-22. 



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

 a spreading base; branches from 2.50 to a little more than 3 mm. in width, 

 not expanding before bifurcating; margins parallel; extremities acutely 

 rounded ; width of non-celluliferous marginal space a little less than 50 

 mm.; transverse section flattened-lenticular, abruptly contracting near the 

 margins, greatest thickness .50 mm. ; bifurcations on the specimens observed 

 distant, occurring at intervals of from 12 to 20 mm. or more ; branches 

 diverging at an angle of about forty-five degrees. Cells tubular, nearly 

 parallel with the mesotheca for the greater portion of their length, then 

 abruptly turning and opening directly outward. Intercellular tissue vesicu- 

 lose, vesicles irregularly disposed. Cell apertures circular, pustuliform, diam- 

 eter of the opening from .12 to .15 mm., of the pustules about .25 mm., 

 disposed in parallel, longitudinal rows, very frequently alternating and form- 

 ing oblique, transverse rows ; apertures of the marginal rows a little larger 

 than the others, having a diameter of about .18 mm. Peristomes thin, slightly 

 and equally elevated, not denticulated. Ranges of apertures separated by thin, 

 moderately elevated striations, of which there are usually one or two between 

 adjacent rows, but occasionally more ; these are generally continuous, but 

 sometimes tortuous and interrupted, and occasionally so numerous as to 

 somewhat obscure the cell apertures Sometimes the cell apertures are very 

 prominent, the bases of the pustules being in contact and presenting a 

 crowded or confused appearance. 



Formation and locality. Hamilton group, Moscow, Livingston county, N. Y. 



Stictopora striata, n. sp. 



PLATE LXin, FIG. 22. 



ZoARiUM consisting of a flattened dichotomously branched frond arising from 

 a spreading base. Branches from 3 to 4 mm in width ; margins sometimes 



