158 



Bryozoans of the 



the intercellular spaces regularly puucturcd or pitted as if by numerous 

 minute cell-apertures — entire intercellular space vesiculose, 



IXTRAPORA rUTEOLATA, n. SJ?. 



Bifurcations occurring at intervals of from six to eight mm., 

 branches variable in width, on most of the specimens observed from 

 two to four mm., but on some 20 mm; forming lamcllose ' expan- 

 sions; greatest thickness one mm., width of non-celluliferous margin 

 .5 mm., base of frond thin, spreading; attached to foreign sub- 

 stances, cells for about one-half their length parallel to the mesial- 

 plate, then abruptly turning and opening directly outward : aper- 

 tures oval, length .23 mm., occasionally circular, sometimes irregularly 

 disposed, at other times quite regularly arranged in oblicpre ti'ansverse 

 rows at an angle of 45° to the margin of the branch, closely arranged, 

 margins strong and equally elevated ; intercellular space occupied by 

 minute angular pits, variable in shape and size, usually a sin,gle series 

 between two adjacent apertures, sometimes two and very rarely three; 

 these pits cover the non-celluliferous margin of the branch. 



Locality — Falls of the Ohio river. 



THAMES OPORA, noi\ gen. 



Bryozoum a narrow branching stipe, the principal stipe and 

 branches celluliferous on both sides. The divisions are not by bifur- 

 cation as in Stictopora, but by lateral and abrupt divergence from 

 the main stipe. 



Tkamxopora diyaricata, n. sp. 



"Width of stipe 1 to 1.25 mm., thickness at the middle .45 mm., 

 width of lateral branches .50 mm., diverging from the stipe at an angle 

 of 90°; cell-apertures oval , length .30 mm., arranged in two longi- 

 tudinal parallel rows : sometimes three rows on the main stipe for a 

 short distance occur; width of non-celluliferous marginal space of the 

 main stipe about .25 mm., on the lateral branches very narrow or en- 

 tirely wanting; longitudinal ranges separated by a ridge, which is fre- 

 qyently elevated above the margin of apertures, angular, giving to the 

 branch a subangular appearance; margins of apertures distinctly and 

 equally elevated; margins of branches usually entire, but sometimes 

 serrated. 



Locality — Near Buffalo, ]^^. Y. 



PRISMOPORA, nov. gen. 



Consisting of triangular branches, frequently forming irregular 

 groups, sides equal or unequal, sabangularly concave, celluliferous on 



