Gexera of the Xortii Americax Palaeozoic Bryozoa. 543 



ity of the acutely oval aperture, there is a small cell, which is 

 best seen in- a tangential section; surface with irregular longi- 

 tudinally channeled spots." (Ulrich ) 



Stictoporena, Hall. 

 (Pal. K Y., Yol. YI, p. 20. 1887.) 

 Type, Stictoporina claviformis^ Hall. 



(Plate 10, figs. 1, 2.) 



Zoarium obtusely pointed at the base, enlarging above and 

 becoming flattened ; bifurcations few ; cells tubular, arising from 

 a mesotheca; apertures oval, disposed in diagonally intersecting 

 rows ; interapertural space elevated, angular, enclosing the aper- 

 tures in rhomboidal or polygonal areas. 



Family Clathroporidae. 



The forms of this family are similar to those of PriLODicTv- 

 iD^ in the form and arrangement of the cell apertures, but 

 they consist of fenestrate fronds, arising directly from a spread- 

 ing base. 



Clathropora, Hall. 



(Pal. K Y., Yol. II, p. 169. 1852.) 



Type, Clathropora frondosa, Hall. 



Original diagnosis. " Eamose or reticulate corals ; uniformly 

 poriferous on both sides of the reticulate fronds and all sides and 

 branches of the stems of the ramose forms ; apertures of cells 

 more or less quadrangular ; regularly arranged in series parallel 

 to the direction of the stems or obliquely in quincunx order." 



Two forms which can not be placed in the same genus were 

 embraced in this description. The forms which have been con- 

 sidered for the past forty years as Clathropora have the same gen- 

 eral appearance and manner of growth as Coscinium, but the cell 



