BRYOZOA. 



401 



Type : #. fucula n. sp. Cincinnati group. Manitoba, and Wil- 



mington. 111. 



Fig. 15. Sceptropora facula n. sp. Cincinnati group, Stony Mountain, Manitoba.* a. 

 A segment of the average size and appearance. b. A vertical section, showing tubular 

 zooecia and central axis . c. Transverse section of lower half of a segment, d. Transvers e 

 section of expanded portion of a very large segment. All magnified to 18 diameters. 



The segments vary in length from less than one mm. to nearly two mm.; the width 

 of the expanded top from 0.7 mm. to 2.0 mm. I am indebted to Prof. J. F. Whiteaves, 

 the palaeontologist to the Geological and Natural History Survey of Canada for the 

 opportunity of describing this unique species. 



HELOPORA Hall. Zoaria composed of subequal cylindrical 

 segments, articulating terminally, poriferous all around. Zooecial 

 tubes somewhat oblique, straight or geniculated. Apertures 

 sub-oval, arranged between slightly elevated lines, or in dia- 

 gonally intersecting series. Inferior border often prominent, 

 sometimes also bearing an acanthopore. 



Type: H. fragilis Hall. Range, Trenton to Niagara. 



XEMATOPORA n. gen. Zoaria very slender, ramose, continuous 

 above the pointed basal extremity. Zooecia sub-tubular, short, 

 arranged in a radial manner around one or two minute axial 

 tubes. Apertures ovate or sub-circular, with peristome, gen- 

 erally arranged between longitudinal ridges. One or two dia- 

 phragms occasionally present. 



Type: N. quadrats, n. sp. Trenton group. Range, Trenton 

 to Niagara. 



Family RHABDOMESONTID.E Vine. 



Zoaria ramose, solid, or with an axial tube. Zooecia with the 

 primitive portion tubular; hemisepta usually developed. Aper- 



* I have lately collected this species at Wilmington, 111., a locality that has proven 

 exceedingly rich in Bryozoa. Also at Savannah, I1L 



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