Gexeea of the Xokth American Palaeozoic Bryozoa. 531 



ring like, and usually completely isolated and the interspaces 



solid." (Ulrich.) 



Phtllodictya, Ulrich. 



(Jour. Cin. Sec. Nat. Hist., Yol. Y, p. 153. 1882.) 



Type, Phyllodictya frondosa, Ulrich. 



"Zoaria leaf-like or consisting of irregular, broad branches. 

 Zooecia tubular, the prostrate portion long, apertures circular, 

 slightly oblique, with the posterior portion elevated ; inter- 

 spaces wide, solid, traversed •vertically by numerous minute 

 tubuli." (Ulrich.) 



'igi 







y^^-o-r- 



FiG. 88. Phyllodictya frondosa. 



Upper fig. , natural size. « 



Lower left hand fig., a portion of the surface xl8. 



Lower right hand fig., a transverse section of the cell tubes, xl3. 



Prismopora, Hall. 

 (Bryozoans of the Upper Helderberg Group, p. 17. 1881.) 

 Type, Prismopora triquetra^ Hall. 



(Plate 12, figs. 9-15.) 

 Zoarium ramose ; consisting of triangular branches, bifurcating 

 or sometimes trifurcating; frequently forming irregular groups; 

 branches with the sides equal or unequal, concave ; celluliferous 

 on each face ; cells tubular, arising from the mesial plates, which 

 extend from the center of the branch to each angle ; margins of 

 the branches solid ; intercellular tissue vesiculose. 



