15 
chyme is seen to vary and the tabulae may be more numerous (up to thirty- 
five in 10 mm.) and more regular than in Billings’ specimen. On Akpatok 
island the variety is represented by four specimens (S.M. A6693, A6694, 
A6691, A6692) which on the whole have corallites rather less distinct 
than in the type and tabulae a little less numerous, Plate III, figure 7. 
A specimen in the G. J. Hinde collection (B.M. R21761) collected from 
Credit river, west of Toronto, and labelled “ Columnopora cribriformis 
Nicholson,” must be regarded as belonging to this variety. Much of the 
inter-corallite structure is removed and its place taken by dolomite; its 
corallites are less distant than in the type and the tabulae are more remote 
(seventeen in 10 mm.). The C. canadensis collected by Kindle (1911, 344-6) 
from Don river, Seward peninsula, Alaska (U.S.N.M. 235) has a wide 
stereozone and is a typical C. canadensis var. anticostiensis. I have also 
examined a specimen from the Silurian (AVhitehead) from near Perce, 
Quebec (U.S.N.M. 90989) and this is identical with Billings type of C. 
anticostiensis. 
The writer has also examined a specimen collected by Per Schei in 
1899 from Norman Lockyer island, Ellesmere island (P.M.O. A8616) 
Plate III, figures 5a-c. There are two specimens, of which this is one 
bearing the same label, in the Schei collection and these were referred by 
Holtedahl (1913, 9, and 1917) to C. canadensis. Holtedahl mentions (1913) 
“ one colony ” only, but Dr. Strand informs me that there is another besides 
the one I have sectioned. This specimen is excellently preserved in nearly 
pure limestone and shows the characters of the variety anticostiensis very 
clearly. It is part of a radiating mass. At the surface the calices have a 
diameter of 2-5 mm. or less; the “ costae” show very distinctly, especially 
in a weathered longitudinal face where they are seen cutting the diaphragms 
of the coenenchyme to give a very characteristic rectangular lattice pattern. 
The corallites are fairly closely approximated, being separated by a dis- 
tance of about half their diameter. In longitudinal section the costae are 
seen to lie horizontally and may in some cases meet those from another 
corallite. The tabulae are nearly all complete and fairly regularly trans- 
verse; there are about twenty in 10 mm. The horizon of this specimen is 
considered in the stratigraphical part of this paper. 
In the material collected by Kiaer from Horizon 5b at Ostre 
Svarto, Ringerike, Norway, there are three specimens which he listed 
(1897) as Calapoecia cf. anticostiensis Billings. These can be satisfactorily 
identified with var. anticostiensis (P.M.O. 14959, 14960, 14965). They are 
not very well preserved and have a peculiar outward appearance. None of 
the original surfaces of coralla remain. All are portions of large radiating 
coralla. In thin sections they closely resemble the Norman Lockyer 
Island example. The corallites are smaller, however, with a diameter usually 
less than 2 mm.: they may be distant or fairly closely placed. 
In an endeavour to investigate Lindstrom’s species C. amphigenia, 
the writer was lent three specimens and one slice from the collection of the 
Naturhistoriska Riksmuseets, Stockholm. One of them (N.R.S. Ca. 602) 
is labelled Calapoecia amphigenia and came from Osmundsberget, Dalarne 
(the type locality), the others are Calapoecia sp.” Beyond this the 
writer is unable to get further information with regard to Lindstrom’s type. 
The type locality of C. amphigenia is Leptaena limestone of Osmundsberget, 
11476 — 
