Bryozoa of the Hamilton G-roup. 65 



side of adjacent branches frequently contiguous ; coalescing; bifurca- 

 tions distant from each other from two to ten centimetres or even more ; 

 width of branch .5 mm., eight in the space of five millimetres ; on non- 

 poriferous side the branches are angular and carinated ; where two 

 branches or the carinations of two branches unite there is very fre- 

 quently a small spine or node. 



Dissepiments or points of anastomosing about .66 mm. wide, four 

 in the space of five millimetres ; sometimes the branches simply anas- 

 tomose; at other times there is a short dissepiment. 



Fenestrules small, oval, .66 mm. in length ; width about one-half 

 the length. On the poriferous side the branches are angular. 



Cells in two ranges, opening nearly directly upward, apertures mi- 

 nute, circular, about .20 mm. in diameter, closely arranged ; distance 

 between apertures less than the diameter of an aperture; sometimes 

 nearly contiguous, eighteen in the space of five millimetres; margins 

 distinctly elevated ; space between ranges of apertures angular, cari- 

 nated ; carina sharp, sinuous, elevated about .20 mm. 



The non-poriferous face presents a variety of phases ; sometimes the 

 carinas of adjacent branches unite and immediately separate, leaving 

 the point of union merely a point which generally has a node or spine, 

 and presents the appearance of a diamond-shaped elevation inclosing 

 the fenestrule, sometimes they remain united for the space of half a 

 millimetre or more, at other times they do not meet and the space 

 between is sometimes channeled, and at others there is a transverse 

 carination, connecting the two longitudinal carinations. This latter 

 form occurs where the branches are united by dissepiments instead of 

 anastomosing, and presents the appearance of an hexagonal elevation 

 inclosing the fenestrule. 



This species is very similar to F. perundulata on the non-porifer- 

 ous face and without very critical comparison it would be difficult to 

 distinguish them ; but on the poriferous face the difference is more 

 evident. In this species the carina separating the row of apertures is 

 thin, sharp, highly elevated and very sinuous. In F. perundulata. 

 it is strong, elevated equal to the thickness of the branch expanded at 

 the top, and straight. 



Formation and locality. Hamilton group; West Bloomfield, New 

 York. • 



/ / Eenestella perforata, n. sp. 



Bryozoan consisting of large infundibuliform fronds ; fragments 

 are of six centimetres in length and five in breadth, evidently only a 

 small portion of the frond; thickness of frond one and one-half milli- 

 metres; frond consisting of numerous cylindrical branches which fre- 

 quently and irregularly bifurcate, and are connected by dissepiments ; 

 along the middle of the branches and dissepiments on the celluliferous 

 face there is a keel or carina, which is elevated and expands above, 

 forming secondary branches and dissepiments very similar in appear- 

 ance to the principal ones. 



Branches moderately strong, about .5 mm. in width, eight branches 

 in the space of five millimetres; branches regularly sinuous, forming 

 [Sen. Doc. No. 53.] 



