BRYOZOA. 527 



attached to foreign bodies by a slightly expanded base. Cell 

 apertures arranged in four or five longitudinal series, occupying 

 the center of the branch, sending off alternate lateral series, com- 

 posed of three or four irregular rows extending to the margins. 

 Between these lateral series are concave granulo-striate non-cel- 

 luliferous spaces. The elevated ridges between the longitu- 

 dinal series bear a considerable number of blunt spines. Cell 

 apertures about seven in two mm. measuring down the rows; 

 oval, about 0.10 mm. in longer diameter; width of end spaces 

 about one and a half times the diameter of the apertures. Zo- 

 oecial tubes prostrate for a short distance, then abruptly bent 

 outward. Between the zooecia are vesicles or mesopores, which 

 do not show at the surface and are provided with very thick 

 diaphragms. The interspaces between the zocecia and the non- 

 cellnliferous portions are occupied by exceedingly numerous 

 minute tubuli. 



The peculiar arrangement of the zooecia distinguishes this spe- 

 cies from all Stictoporoid Bryoza known to me from the Ham- 

 ilton group, with the exception of Stictopora palmipes Hall. 

 That species, if I have correctly identified it, is closely allied to 

 the one above defined, and clearly congeneric with it. It differs 

 in being wider and scarcely branched, nor have I found it at 

 Buffalo, Iowa, where E. serrata is fairly abundant. 



These species I regard as quite distinct from Stictopora, the 

 minute structure and the arrangement of the zooecia being very 

 different from what we find in typical species of that genus. 

 The following species does not belong in this association, but 

 is provisionally placed here till we can find a more fitting re- 

 ceptacle for it. 



EUSPILOPORA ? BAKRISI UMcll. 



PI. XLIII, Fig. 5-5d. 



Zoarium dichotomously branched, stipe with non-celluliferous 

 margins, from two to four mm. wide, and one to four mm. in 

 thickness. Transverse section strongly double convex. Aper- 

 tures sub-polygonal or sub-circular, slightly oblique, 0.2 mm. or 

 a little less in diameter, between eight and nine in three mm., 



