BRYOZOA. 535 



FENESTELLA VERA Ulrich. 



PI. XIJV. flgs. 1, la, and PI. IJV, fig. 3. 



Zoarium a somewhat undulating flabellate expansion; largest 

 fragment seen over 6 cms. in length. Obverse with branches 

 rather straight, slender, ridge-shaped, bifurcating at distant in- 

 tervals, about 0.35 mm. in width, and twenty-four in 1 cm. 

 Dissepiments short, sub-carinate, varying in width from about 

 two-thirds to almost the width of the branches. Fenestrules 

 elliptical or sub-quadrangular, about 0.5 by 0,2 mm.; fourteen 

 in 1 cm. Carina prominent, not sharp, bearing small nodes 

 about twice their diameter apart, and six or seven in 2 mm. 

 Xorecia in two ranges. Apertures small, circular, opening ob- 

 liquely into the fenestrules, generally four to each fenestrule, 

 and twenty-three in 5 mm. On the reverse the branches are 

 usually zigzag, on the same level and scarcely stronger than 

 the dissepiments, the fenestrules have a somewhat hexagonal 

 shape, less marked in the older portion of the zoarium, and 

 form quite regular diagonal series. Surface of both branches 

 and dissepiments very minutely granulose. 



This species was at first supposed to be identical with Front's 

 F. nodosn, but upon a careful comparison with his description, 

 I find that the measurements do not agree. The flexuous char- 

 acter of the branches on the reverse is perhaps the principal 

 peculiarity, and serves to distinguish the species from several 

 Devonian forms that approach it in other respects. 



Position and locality: Hamilton group. Abundant at Buf- 

 falo, Iowa. 



FENESTELLA FILISTRIATA Ulrich. 



PL XLIX, fig. 2, 2a. 



Zoarium a flabellate expansion, with the margins curved so 

 as to give to the whole a semi-funnel shape. Base slender, 

 solid, with root-like processes. Branches lax, rather slender, 

 subcarinate. 0.35 to 0.5 mm. wide, and about four in 3 mm. 

 Dissepiments slender, striated, varying in length. Fenestrules 

 subquadrangular, much longer than wide, about six in the 



