I70 NEW YORK STATE MUSEUM 



ous on one side only, deeply striated longitudinally on the other; 

 quadrangular or subrhomboidal apertures; branches often thickened 

 or clavate, always obtuse. 



Found in the upper part of the lower Rochester shale and the 

 Bryozoa beds at Niagara. Rare. Also at Lockport (Hall). 



Genus fenestella Lonsdale 



[Ety.: fenestella, a little window] 



(1839. Murchison. Silurian system, p. 677) 



Zoarium consisting of a calcareous branching frond, forming cup- 

 shaped or funnel-shaped expansions. The branches fork, and are 

 connected by transverse bars or dissepiments, thus inclosing spaces 

 or fenestrules. The cell apertures occur only on the inner side of 



^---■_ nil 

 < • ■ ■ , \ pi 



#$$' mm 





■Hi 



J 



'J 



Fig. 70 Fenestella elegans with enlargements 



the branches. They are surrounded by rims or peristomes and 

 are arranged in two parallel rows, while between them occurs a ridge 

 (carina) or a row of nodes. 



Fenestella elegans Hall (Fig. 70) (1852. Pal. N. Y. 2:164, pi- 

 40D, fig. ia-g) 



Distinguishing characters. Carina subdued; apertures with their 

 longer diameter oblique to the direction of the branches; branches 

 slender, frequently bifurcating; thin and slender dissepiments 

 scarcely enlarging at the junction with the branches; fenestrules on 



