186 



Bryozoans of the 



margins thin, very slightly elevated; intermediate space occupied by 

 minute angular pits. There are numerous conical nodes or spines sit- 

 uated between adjacent cell-apertures, the base occupying the space 

 oetween them. 



Locality —Hamburg, N. Y. 



Thallostigma dens a, n. sp. 



Expansions; cells tubular, apertures oval, circular, polygonal, di- 

 ameter .25 mm., closely disposed, some portion ot adjacent cells usually 

 touching, frequently disposed in comparatively straight lines; inter- 

 mediate space occupied by angular pits ; maculae from 2 to 3 mm. dis- 

 tant, composed of cells which are usually subpolygoual and larger 

 than others. 



Locality — York, N. Y. 



Thallostlgma micropora, n. sp. 



Expansions; greatest thickness observed .33 mm. ; apertures nearly 

 circular, diameter .20 ram., irregularly disposed, margins thin, ele- 

 vated ; intermediate space occupied by minute angular pits about 10 

 in the space of 1 mm. ; from one to three series between adjacent 

 apertures. 



Locality — Eighteen Mile Creek, Erie county^ N. Y. 



Thallostigma segregata, n. sp. 

 Expansions; cells tubular, cylindrical; apertures broadly oval qr 

 circular, diameter .33 mm., margins strong, distinctly elevated, irreg- 

 ularly disposed; intermediate space occupied by minute angular pits, 

 from one to four series between adjacent apertures. This is similar m 

 appearance to T. 7nicropora, but the cells are much larger. 



Locality — Eighteen Mile Creek, Erie county, K. Y. 



Thallostigma striata, w. sp. 



Expansions or masses formed by accretions of growth; cells tubu- 

 lar, cylindrical, walls thick, non-septate ; apertures broadly oval or 

 circular, diameter .25 mm., sometimes irregularly disposed, at other 

 times quite regularly distant from each other about the diameter of an 

 aperture; intermediate space with angular pits, usually about 10 in the 

 space of 1 mm., but sometimes as large as the cell-apertures , usually 

 so arranged as to give a striated appearance to the surface. 



Locality — Hamburg, N. Y 



