222 PALEONTOLOGY OF NEW YORK. 



apertures ; from all other species, at present known in this formation, it is 

 distinguished by its smaller cell apertures and extremely minute mesopores. 



Formation and locality. Shales of the Hamilton group, two and a lialf miles 

 east of Alden station, Erie county, N. Y. 



FiSTULIPORA TRIFARIA, n. Sp. 



MOT FlaORBD. 



ZoARiUM consisting of free or incrusting explanate fronds ; greatest observed 

 thickness about 1 mm. Cells tubular, cylindrical, rectangular to the surface ; 

 septa very thin and infrequent. Intercellular space vesiculose; near the base 

 the vesicles are large and very irregularly disposed ; they are somewhat 

 more regularly superimposed above, but never having the appearance of 

 septate tubuli in the specimens observed. Cell apertures trilobate, length 

 about .30 mm., width slightly less, irregularly disposed, sometimes in con- 

 tact, at other times distant the diameter of an aperture or even more. 

 Peristomes thin, equally elevated, apparently not denticulated, sometimes 

 having minute nodules or spinules. Mesopores variable in size, frequently 

 nearly as large as the cell apertures. Surface marked by elongate, slightly 

 depressed maculae, disposed at irregular intervals. 



The cell apertures of this species most nearly resemble those of Lichenalia 

 vesiculata, but it is easily distinguished by the presence of mesopores. 



Formation and locality. Hamilton group, Fallbrook, four miles east of Canan- 

 daigua lake, N. Y. 



FiSTOLIPORA TRIANGULARIS. 



NOT FIGURED. 



Thallostigma triangularis. Hall. Trans. Albany Institute, vol. x, p. 187. 1881. 

 " " " Report of State Geologist for 1883, p. 32. 1884. 



ZoARiTJM consisting of free or incrusting lamellate expansions, or of masses 

 formed by the accretion of successive layers of growth ; thickness of a 

 single layer 1 mm. ; under surface a thin epitheca, concentrically wrinkled 

 and striated. Cells tubular, cylindrical, oblique. Intercellular tissue vesi- 

 culose ; near the base the vesicles are very irregularly disposed, and 



