APPENDIX IV. 327 



horizon and district, the corallites are generally smaller (from 3 to 

 7 mm. in diameter). As suggested by Dr. Whiteaves in his original 

 description, additional material with corallites of intermediate size 

 may prove the two forms to be specifically identical. 



Of the corals from Southampton island, Streptelasma robustum 

 indicates the presence of beds at this locality that belong to the same 

 horizon as those that have been assigned to the Galena-Trenton in 

 the Lake Winnipeg region, and similar beds exposed over a large area 

 to the west of Hudson bay. The beds from which the other species 

 from the same island are derived belong to higher horizons which are, 

 on the evidence of these species, of about the same geological age as 

 those of the Niagara and Guelph formations of Ontario. 



CAPE CHIDLEY, HUDSON STRAIT. 



A single coral from this locality is represented by two fragments 

 that have apparently been broken from a larger mass. The exact 

 form of the corallum is unknown, but the structure of the corallites 

 is well preserved and clearly seen in longitudinal and traverse sec- 

 tions. Its structural characteristics are quite different from those 

 of any form known to the writer, and it is regarded as representing 

 a new genus and species named and characterized as follows: 



Labyrintliites. Gen. nov. 



Corallum massive, made up of very slender, long, columnar cor- 

 allites, upwardly directed and parallel, each one connected along the 

 whole of its length with two or three adjacent corallites in tortuous 

 series separated by narrow interspaces. Tabula?, complete, distant. 

 No septa nor tubules. 



Although the manner of growth of this coral resembles somewhat 

 that of Halysites it could scarcely be referred to that genus, on 

 account of the absence of septa and tubules, although in Halysites 

 catenularia var. gracilis tubules are apparently wanting. The small 

 size of the corallites would not necessarily be considered a character 

 sufficient to constitute generic distinction. Another genus, Fletclieria, 

 may be considered, but Labyrinthites has little in common with it. 

 In both, the tabute are distant and simple, practically the only point 

 of resemblance unless we notice the small size of the corallites of 

 Fletcheria and the stated rudimentary condition of its septa. 



