B R YO Z O A. 



(FENESTELLID.E) 



OF THE 



HAMILTON GROUP. 



By James Hall. 



, e/ Fenestella multiplex, n. sp. - _ / 



Bryozoan, occurring only in fragments ; the shape of the frond is 

 uncertain,but probably is infundibuliform ; fragments of six centimetres 

 in width occur, evidently only a small portion of the whole frond. 



Branches moderately strong, enlarging below the bifurcations, and 

 the width just above bifurcation is .33 mm., below bifurcation .66 mm. 

 or slightly less. The distance between the branches is variable ; there 

 are on different portions of the frond five or six branches in the space 

 of five millimetres ; on non-poriferous side the branches are angular, 

 and have along the middle a slight keel or carina, which connects with 

 a similar carina on the dissepiments ; when the dissepiments on oppo- 

 site sides of a branch are alternating, the carina of the branch, in con- 

 necting with the carina of the dissepiment, becomes zigzag, which 

 causes the branches to appear more irregular and less rigid than on the 

 poriferous side; the branches are smooth. 



Dissepiments about .25 mm. in diameter, four in the space of five 

 millimetres; on non-poriferous side slightly depressed, angular and 

 carinated ; on poriferous side, depressed, rounded. 



Fenestrules, on non-poriferous side, subquadrangular in outline; on 

 poriferous side oval; length about one millimetre, width varying from 

 one-third to two-thirds the length. 



Cells in from two to four ranges, occurring as follows : In a branch 

 which from commencement to bifurcation is six millimetres in length, 

 for one millimetre only two ranges of cells occur, three ranges for the 



* The species of the present paper only partially represent the genus as occurring in the 

 Hamilton group. It is published in this incomplete form in order to show the progress of 

 the work upon the Bryozoans, and to facilitate the final revision of the species. 



[Sen. Doc. No. 53. | S 



