i88 



Cincinnati Society of Natural History. 



occur in 5 mm. measuring longitudinally. Interspaces occasion- 

 ally subangular between the rows of zocecia ; everywhere exhibit- 

 ing a very fine granulo-striate character. Non-periferous margins 

 inconspicuous, generally wider on one side than on the other. 



The subhexagonal narrow branches of this species present con- 

 siderable resemblance to species of Nematopora like N. lineata 

 {Helopora lineata, Billings). Of course, there is no real affinity 

 between them, this being, as is clearly shown by transverse 

 sections, a bifoliate zoarium, while in Nematopora the zooecia 

 diverge equally in all directions from the center of the branch. I 

 am not acquainted with any species of Pachydictya, nor with any 

 associated species of bryozoan, with which the slender ramulets of 

 P. triserialis might be confounded. 



Position and locality: Trenton limestone, Montreal, Canada. 

 The specimens, together with other Bryozoa, received in exchange 

 from the Peter Redpath Museum, were collected by Mr. T. C. 

 Curry. 



ST1CTOPORELLA RIG1DA, n. sp. 



Fig. lS.—Stictoporella rigida, n. sp. a, a bifurcating branch of this species, natural 

 size, and part of same x9. b, portion of same x!8, showing the arrangement of the 

 zooecia apertures, interstitial pits or mesopores, and character of margins. 



Zoarium a narrow branching, bifoliar stipe. Branches flattened, 

 1.0 mm. or a little more wide, with straight parallel and sharp 

 margins, acutely elliptical in cross-section. Zocecia in seven to 

 nine or ten rows on each face, their apertures arranged in very 

 regular longitudinal and diagonally intersecting series, with six- 



