APPENDIX IV. 323 



Two specimens of corals from Beechey island are not referable to 

 any genus with which the writer is acquainted. In these specimens 

 the structure is revealed, by weathering at the calicular surface and 

 in horizontal and longitudinal sections, as well as in sections obtained 

 by rubbing down and polishing. As the writer is unable to place 

 this coral, to his satisfaction, in any described genus, it is thought 

 best to establish a new genus for its reception. The main generic 

 characters are enumerated below with a brief description of the 

 species which the writer has much pleasure in naming after Mr. 

 Low. 



Boreaster. Gen. nov. 



Corallum composite, massive (or thickly incrusting), made up of 

 intimately connected polygonal corallites communicating with each 

 other by means of mural pores. Septa in the form of longitudinal 

 lamellae, twelve in number. Tabulae simple. 



This genus resembles Favosites in having numerous pores in the 

 walls of the corallites, but differs from it in the possession of lamellar 

 septa somewhat similar to those of Columnaria, Nyctopora and 

 Lyopora. From these three genera, however, Boreaster differs in 

 having 12 septa only, of two alternating sizes, to a corallite. Column- 

 aria and Lyopora are without mural pores. Nyctopora was described 

 by Nicholson as having pores, but in well preserved specimens from 

 the type locality, examined by the writer, mural pores were not seen; 

 it possesses 16 septa of two orders. Boreaster and Calapoecia resemble 

 each other in both having pores, but in the latter genus the corallites 

 are not intimately united under any circumstances, and the septa 

 are in the form of spine-bearing ridges. 



This interesting coral may be conveniently grouped with the 

 Favositidce, as its generic affinities appear to place it close to Cala- 

 poecia. 



Boreaster lowi. Sp. nov. 



Corallum growing in irregularly shaped masses with an unevenly 

 undulating surface; composed of small, polygonal corallites so closely 

 united that all trace of the line of contact between contiguous walls 

 is apparently lost. Corallites opening at right angles to the surface, 

 averaging about 75 mm. in diameter and generally five or six sided, 

 as seen in transverse section, the sides of the polygons being distinctly 



