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Genus FENESTELLA. Miller. 



[Ety. : Fenestella, little window.] 

 (1839: Lonsdale in Murchison's Sil. System, I't. II., p. 677.) 



Bryozoum, consisting- of a calcareous brandling frond, 

 forming cup-shaped or funnel-shaped expansions. The 

 branches fork, and are connected by transverse bars or dis- 

 sepiments, thus enclosing spaces or fenestrules. The cell 

 apertures occur on one side of the branches. They are sur- 

 rounded by rims or peristomes, and are arranged in two 

 parallel rows, while between them occurs a ridge (carina), 

 or a row of nodes. 



Fenestella emaciata. Hall. (Fig. 47.) (36th Ann. 

 Rep't N. Y. State Mus. Nat. Hist,, p. 68, 41st Rep't, do., PI. 

 Till.) 



Distinguishing Characters. — Large, funnel-shaped frond; 

 longitudinal striations of branches on the non-celluliferons 

 face, with thin, oblique dissepiments; angular character of 

 branches, and dissepiments on celluliferous face; closely and 

 regularly disposed cell apertures. 



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



% 





""*H 



Fig. 47. Fenestella emaciata (from Hall), (a) Fragment of frond, reduced ; i/i) an en- 

 largement from the non-celluliferons face, showing the striated granulose branches, and the 

 oblique dissepiments. 4 x : (c) an enlargement from the celluliferous lace, sin .wing the form 

 and disposition of the cell apertures, 4 x : (d) a transverse section of the branches, 4 x : 

 (ei a lateral view of the branches, showing the dissepiments and position of the apertures. 

 4 x. 



Fenestella planiramosa. Hall. (Fig. 48.) ('Kith Ann. 

 Rep't N. Y. State Mus. Nat. Hist., p. 62; Rep't State GeoL, 



1887, PL I.) 



