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the side of the adult, and gradually attain their full size. Surface with 

 fine transverse striae of different sizes, usually five or six in one lme f 

 crossed by obscure septal striae. 



The inner wall is excessively thin, and in some individuals appears to be 

 absent altogether ; but in many it is distinctly visible. The size of the 

 inner area varies, as it does in all species of this genus, but in general it 

 is one-third the width of the corallite. 



Locality and Formation. Becsie River Bay, Anticosti ; in Division 2, 

 Anticosti group, Middle Silurian. 



Collector. J. Richardson. 



CYATHOPHYLLUM INTERRUPTUM. (N. sp.) 



Description. Corallum apparently simple, turbinate, curved, gradually 

 expanding to a width of Ij inches in a length of 5 inches; irregularly 

 annulated by sudden constrictions and expansions of growth, from f to 1 

 inches. apart. The transverse section, where the diameter is 1 inches, 

 shows about 120 radiating septa, which seem to reach half-way to the cen- 

 tre. On the outside, where the surface is a little worn, the septal striae 

 are well indicated, and the interseptal spaces divided into square compart- 

 ments by the transverse diaphragms. There are about 3 septal striae in 

 1 line. The cup appears to be about f of an inch deep, and at the bottom 

 about ^ the whole diameter of the fossil. The internal structure in the 

 longitudinal section cannot be made out in the specimens observed, being 

 obscured by 1 crystallization. 



This species somewhat resembles 0. truncatum (Linnaeus), but is more 

 deeply annulated. The rings on the upper side project at about a right 

 angle from the side, sometimes \ an inch, and gradually slope on the lower 

 side to the narrowest part of the next constriction below, so that the indi- 

 vidual is constructed as if several corallites had been set into each other. 



Locality and Formation. L'anse a le Barbe, Bay of Chaleurs, Middle 

 Silurian. 



Collector. Sir W. E. Logan. 



CYATHOPHYLLUM ANTICOSTIENSE. (N. sp.) 



Description. Corallum rather large, cylindro-turbinate, slightly curved 

 at the base. Cup irregularly conical, its depth about half the diameter of 

 the corallite ; the walls thick ; the margin effuse or obtusely rounded, the 

 inner surface of the cup descending with a convex slope from the outer 

 edge inwards. In the longitudinal section the inner area is about one-third 



