I/O 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.: fcncstcUa, a little window] 



(1839. Murchison. Silurian system, p. 6^/) 



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 



f f 



1h 





f ^ -l> 



,-,-^' 



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 1164, pi. 

 40D, fig. la-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 



