Lower Helderberg Bryozoa and Corals. 109 



Ceramopora (Berenicea) maxima n. sp. 

 Bryozoiim of a depressed convex form, composed of cells which 

 radiate from the center of the disc, and open laterally, inclined at an 

 angle of about forty-five degrees to the plane of the disc near the 

 center, and becoming more prone as they approach the margin. 

 Cell apertures irregularly hexagonal, somewhat elongated from the 

 projection of the anterior or lower margin ; diameter of the opening 

 about one-twentieth of an inch ; cell walls thick, obscurely striate 

 inside, their margins at the angles of the cells prolonged in a spine- 

 like process. Under surface unknown. 



The single specimen found, measures nearly three-fourths of an inch 

 in diameter. It has tlie general features of those Palaeozoic species 

 usually referred to Berenicea, but is much larger than the usual 

 size of those. It resembles a Michelina with very small pores ; but 

 on examination its characters are more of a Bryozoan, especially the 

 projections at the angles of the cell walls. 



Fonnatioii and locality. — In the shaly limestone of the Lower 

 Helderberg group, at Schoharie, New York. 



YERMIPOKA Nov. Gen. 



Bryozoum growing in ramose branches, which are composed of 

 small cell tubes, growing upon each other side by side, without 

 intertnbular or cellulose substance, and destitute of rays, or trans- 

 verse partitions within the tubes. Tubes rising from the center of 

 the branch, gradually diverging, and opening upwards on the exte- 

 rior surface ; each tube forming the apex of the branch at the time 

 of its origin, and giving place to succeeding cells in its diverging 

 outward. 



The Bryozoans referred to this genus are ramose branches, 

 formed by the union of serpula-like tubes, cemented upon each other,* 

 their apertures directed upwards and opening on the side of the 

 branch, increasing in size with the increased diameter of the branch. 

 There are no new cells formed by interstitial additions, the increased 

 size of branch being dependent on the increased size of the tubes 

 themselves. In a transverse section the appearance is of a bundle of 

 compressed tubes, cemented together ; the floor of the outer ones 

 being formed by the exterior walls of the two just beneath it, and 

 between whicli it has been formed. Of this peculiar type of Bryo- 

 zoans we know yet of but two species, one of which is in the Upper 

 Ilelderberg limestone. 



