172 



Distinguishing CJmriicters. — Free or iiicrustiiig lamellate 

 expansions, or masses, formed bv siij)ei'position of successive 



layers of growth; tubular cells, 

 recumbent for a short distance, but 

 chiefly at right angles or oblique to 

 surface; oval or nearlv circular 



of 



mi 







'■0P'.^f ^"^^1 apertures, usually a little ob- 

 licpie to the surface; prominent 

 ^^';9i-^ rounded monticules, bearing an 

 elongate depression in the center, 

 which is destitute of cells: large cell 

 apei-tures adjacent to the depres- 

 sions ; radiating rows of apertures, 

 giving the monticules a stellate 

 appearance. 

 Found in the Demissa bed of Sections (massivespecimens). 



Fig. 66A. LiclienaUd stellata. 

 Portion of the surface enlarged, x 6 

 (after Hall and Simpsou). 



Genus STICTOPORA. Hall. 



(1847: Pal. K Y., Vol. I., p. 73.) 

 [Ety. : Stiff 'js, punctured : poros, pore.] 



Bryozoiim consisting of thin, flat branches with a lenticu- 

 lar cross-section, and attached by a s[)reading base to for- 

 eign objects. Cells in two series, separated by a median wall 



or mesotheca, each series 

 having its apertures on one 

 of the flat sides. Margin 

 without cells. 



Stictopoka ixcisurata. 

 Hall. (Fig. 67.) (Pal, 

 X. Y., Vol. YL. p. 241, PI. 

 LX.) 



Dis tinguisli ing Clia. r a c 



Fig. (JT. i^tictopora incisurata. Natiu'al 

 size and a portion enlarged (after Hall and 

 Simpson). 



ters. — Elongate oval 



to 



nearly circular apertures in 

 longitudinal diverging lines, increasing by interstitial ad- 

 ditions; marginal apertures largest; peristomes strong ; 



