CLEIOCRIXUS. HI 



Tegraen unknown, but presumably consisting of a flexible plated 

 integument. 



Column large, moderately long (over ten inclies in the one specimen 

 preserved), terminating in an expanded root for attachment to solid 

 surfaces. It is pentagonal in the upper portions, interradially disposed, 

 composed of rather thin ossicles, the alternate ones thicker near the 

 calyx and slightly projecting, but becoming more uniform and thinner 

 toward the distal end. The proximal portion does not taper, but the 

 distal portion becomes round and suddenly enlarges near the root. Axial 

 canal very large, pentagonal, the angles interradial and coinciding with 

 the exterior angles of the column. 



Horizon and Locality. Ordovician ; from the Trenton Limestone. City 

 of Ottawa, Canada. 



The type specimens are in the Museum of the Geological Survey of 

 Canada at Ottawa. 



Cleiocpjxus magnificus Billings. 



Calyx very large, robust, narrow at the base and broadly expanding 

 toward the arm bases, thus being cup-shaped instead of conical. 



General structure of calyx and arms, so far as known, similar to that 

 of C. regius, but with a much greater brachial development, giving rise 

 to about one hundred free arms. 



Column very large, round externally except in the upper portion, 

 where column and axial canal are obscurely pentagonal ; ossicles much 

 thinner than in C. regius, averaging sixty to the inch, as compared with 

 about thirty to forty in that species. The column is over thirty inches 

 in length, enlarging in the specimen found from half an inch in diameter 

 near the proximal end to seven eighths of an inch at the distal end, where 

 it terminates in a broadly expanded root. Maximum diameter of column 

 fragments a little over one inch. 



Horizon and Locality. Ordovician ; from the Trenton Limestone. Hull 

 cp_iarries, near the City of Ottawa, Canada. 



The type specimens are in the Museum of the Geological Survey of 

 Canada, at Ottawa. 



