Bryozoa of the Hamilton Geoup. 69 



of branches from .33 to .50 mm.; space between about equal to the 

 width of the branches ; seven branches in the space of five millimetres ; 

 on non-poriferous side, rounded, striated; striae moderately strong, from 

 three to five on a branch ; finely granulose ; sometimes the central stria 

 resembles a narrow carina. 



Dissepiments about .25 mm. in width ; six in the space of five mil- 

 limetres ; slightly expanding at their junction with and oblique to 

 the branches ; angle of obliquity from ten to twenty degrees ; on non- 

 poriferous side moderately depressed, rounded, transversely striated, 

 granulose ; on poriferous side, very much depressed, slightly angular, 

 carinated ; carina slight. 



Fenestrules oval or subquadrangular ; length .66 mm. ; width from 

 .33 to .50 mm. 



Cells in two ranges opening laterally ; apertures small, .20 or .16 mm. 

 in diameter, closely arranged, frequently nearly contiguous; from 

 twenty to twenty-five in the space of five millimetres ; margins elevated 

 and indenting the border of the fenestrule. 



Space between the ranges of apertures elevated, height equal to one- 

 half the thickness of the top of the branch; slightly rounding; not 

 acutely angular, having a row of nodes ; nodes minute ; frequently 

 wanting. 



This species differs from F. marcida by having stronger, more widely 

 separated branches; dissepiments farther apart and oblique to the 

 branches ; on the poriferous side the cells open more laterally ; the 

 space between the cells is elevated, not carinated, and comparatively 

 thick, and without the closely arranged, prominent nodes of that 

 species. 



Formation and locality. Hamilton group, shore of Seneca lake, N. Y. 



^ Fenestella cuevata, n. sp. 



s±it% cut** u n^j ^ sicPk Jfr+JofUh £ £. ?/f '- f. 



Bryozoan inf undibuliform ; largest fragments seen four millimetres 

 in length and of about the same width. 



Branches slender, scarcely increasing in size to the bifurcations, 

 which are distant from each other from four to fifteen millimetres, 

 generally about ten millimetres ; width of branches from a little less 

 than .25 to .33 mm., occasionally slightly more ; transverse section sub- 

 cuneiform in outline ; space between branches greater than the width 

 of the branches ; seven branches in the space of five millimetres ; when 

 the dissepiments on opposite sides of the branches alternate, the 

 branch is flexuous, but not when the dissepiments are opposite each 

 other ; on non-poriferous side the branches are rounder, in well-pre- 

 served specimens showing fine, granulose strise, from five to seven on 

 a branch ; generally opposite the dissepiments there is a prominent, 

 conical spine about .25 mm. in height. 



Dissepiments comparatively strong; width nearly or quite equal to 

 that of the branches ; thirteen in the space of ten millimetres ; not 

 expanding at their junction with the branches ; on non-poriferous 

 side slightly depressed, rounding ; on poriferous side scarcely per- 

 ceptible. 



