6 OLAF HOLTEDAHL. M.-N. KI. 
in pl. I, fig. 1), the thickness is only 3 mm. at the maximum. The original 
skeleton of vertically placed spicules appears chiefly as hollows (cells) 
arranged in the characteristic rounded lines. In certain cases as in parts 
of the specimen, fig. 2, however it is found as a true silicified skeleton, 
which with acid has been corroded out of the matrix which possessed less 
power of resistance. Y 
As a rule the discs are so greatly worn that we only see the more 
deeply situated parts of the spicules with a round section, but in some pieces 
(see pl.l, fig. 2 and pl. IV, fig. 3) we can also see the rhombical apertures 
(impression of head plates), with a maximum size of 4 mm. : 
In some of these, belonging to the upper (inner) surface there appear 
to be evidences of the radiating canals or stripes the number of which 
constitutes one of the few characteristics which differentiate Receptaculites 
owem from À. occidentalis SALTER!, although we are not able to make any 
conclusions from the evidence thus afforded. 
The very considerable dimensions, both with respect to the whole 
disc, and also to the size of the openings are conclusive in the deter- 
mination of this form as R. oweni and not the other form. 
The form A. arcticus described by ETHERIDGE from Arctic North Ame- 
rica, shows even greater dimensions, the summit plates being in some 
instances no less than 7 mm. 
A. owem is a typical Trenton (Galena) form. 
Some few fragments of corals are present, although so badly pre- 
served that any detailed account is out of the question. 
We have a piece of a curved Simple Coral. 
Halysites sp. 
Columnaria sp. 
with partly separated corallites. 
Maclurea sp. 
Plate Ib «Eig o: GPL AV, Pigs A5: 
In numerous pieces we discover a series of casts of a gastropod form, 
although in a too incomplete form for any exact conception of the ex- 
terior to be possible. In general only the reverse side or the impres- 
sion of the same can be seen. Originally flat, the whorls have become 
rounded by weathering on this side also. 
1 The two forms are combined by some e. g. Hinde, Quart: Journal, Geol. Soc, Vol. XL. 
