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 : 
Labyrinthites. 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. tabulae, 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, Fletcheria, 
may be considered, but Labyrinthites has little in common with it. 
In both, the tabulae 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. 
