161 



Distinguishing CIi;nncters.— Uv\ iculated aspect of fronds ; 

 oval fenestrates; nine to ten apertures to each fenestrate, 

 completely surrounding it. (On account of the expansion of 

 the carina to nearly the middle of the branches, this face 

 may appear like the non-celhiliferous face, especially when 

 embedded in rock.) 



Found in the Demissa bed, at Section 5 (common ). 



Genus RETEPORINA. D'Ormgny. 



[Ety. : Rete, net ; poros, pore. ] 

 (1850: Prodome de Pal., T. I., p. 101.) 



Bryozoum fenestelloid, with sinuous and anastomosing 

 branches. The non-celluliferous side has the appearance of 

 a net-work, with oval fenestrates; while the celluliferous 

 side shows sinuous branches, with a double row of 

 apertures on each. 



RETEPORINA striata. (Hall.) (Fig. 50.) 

 (6th Ann. Rep't N. Y. State Geol., p. 45, PL III. 

 1886.) 



Distinguishing Cha racters. — Reticulated 

 appearance of frond; frequently a prominent 

 node at point of junction of branches ; sinuous 

 branches of celluliferous face, apparently con- 

 nected by wide, depressed dissepiments; thin, Fl »- so. Rete- 



" x L port no striata. 



elevated and crenulated carina between aper- and "cellnitfCToua 



4-,-n -oo sides, enlarged, x 



luleB - 4 (after Hall). 



Found in the Demissa bed, at Section 5. 



Genes UN1TRYPA. Hael. 



[Ety.: Unus, one; try pa, perforation.] 

 ( 1885: Rep't N. Y. State Geologist for 1884, p. 36.) 

 Bryozoum consisting of fenestelloid fronds, with two 

 rows of apertures, separated by a carina on the celluliferous 

 face of each branch. The carina? are prominent, high, thick- 

 ened near the top, and those of adjacent branches are 

 connected by thin obliquely-placed, or abruptly-bent, trans- 

 verse plates or sc&lae. 



