Genera of the I^okth American Palaeozoic Bryozoa. 535 



Intbapoea, Hall. 



(Trans. Albany Institute, p. 167. 1881.) 



Type, Intrajpora pideolata^ Hall. 



(Plate 11, figs. 1-9.) 



Zoarium consisting of a flattened, dichotomously branching or 

 bifurcatino^ frond, arising from a spreading base ; cells tubular 

 for one-half the lengthy parallel with the mesotheca, then turning 

 abruptly outward; apertures oval, irregularly and very closely 

 disposed ; very frequently in contact ; peristomes strong, slightly 

 and equally elevated. The interapertural space is occupied by 

 minute angular pits, generally a single series between adjacent 

 apertures ; intercellular space irregularly vesiculose. 



Semiopoea, Hall. 

 (Trans. Albany Institute, Yol. X, p. 193. 1881.) 



Type, Semiopora histigmata^ Hall. 



(Plate 11, figs. 10-11.) 



Zoarium consisting of a flattened dichotomously branched 

 frond, proceeding from a spreading base attached to foreign 

 bodies; branches narrow, not expanding before bifurcation ; non- 

 celluliferous marginal space very narrow ; transverse section 

 abruptly narrowing and very thin toward the margin ; obscurely 

 subangular near the middle ; cells tubular, oblique, gradually 

 enlarging to the aperture. The intercellular tissue is composed 

 of irregularly disposed vesicles ; cell apertures oval, sometimes 

 nearly circular ; regularly disposed in parallel longitudinal rows ; 

 the apertures of the marginal rows being larger than the others. 

 Between adjacent cell apertures in a longitudinal direction are 

 two minute pits side by side. In the course of growth these pits 

 form minute tubuli between the cell tubes. 



Stictoporella, Ulrich. 

 (Jour. Gin. Soc. :N'at. Hist., Yol. Y, p. 152. 1882.) 

 Type, Stictoporella interstincta, Ulrich. 



The type species of this genus belongs to Intrapora ; other 

 forms, as S. crihrosa, are members of the genus Goecinella. 



