From the Niagara Formation. 



61 



elevated and granulose margins ; the apertures arranged in spira 

 rows, the distance between them a little more than their length 

 Interspaces covered with fine granules. 



This species is distinguished from T. minuta by the absence of 

 the strong longitudinal rows of nodes, which in that species are more 

 elevated than the cell-margins, while in this the character is reversed. 

 The minute granulas upon the surface show that the differences 

 observed are not due to weathering or maceration. 



Stictopora orbipoka n. sp. 



Bryozoum ramose ; bifurcations frequent, branches convex, thick- 

 ness about half as great as the. width ; margins of branches destitute 

 of cellules, and marked by granulose striae. Cellules rising from 

 a thin diaphragm and ascending at an angle of about 45° for half 

 their length and then turning slightly backward, open upon the 

 surface in small circular apertures which are surrounded by an 

 elevated granulose margin : cellules arranged in oblique lines 

 in which there are sixteen cell-apertures in the space of fiv^e milli- 

 metres. 



This species differs from S. similis in the thicker stipe and the 

 distinctly circular cell-apertures. 



CeRAMOPORA ? (LiCHENALIA ?) EXPLANATA H. Sp. 



Bryozoum consisting of thin foliate expansions, which may be free 

 or incrusting, and celluliferous on one or both sides : when celluli- 

 ferous on one side only, the lower side consists of a concentrically 

 wrinkled epitheca ; and when celluliferous on both sides, this epitheca 

 becomes a thin diaphragm separating the two ranges of cells. Cellules 

 obliquely ascending, and rapidly expanding towards the aperture; 

 arranged in alternating and imbricating series ; apertures oblique to 

 the surface of the frond, opening in an arched or subtriangular 

 form. 



This species occurs in moderately large expansions, presenting 

 the general aspect of Lichenalia concentrica ; but it may readily 

 be distinguished by the angular form of the cell-apertures, and 

 by the direction of the cells being more nearly parallel to the 

 epitheca or diaphragm ; and they are exposed for nearly their whole 

 length. 



