DR. G. J. HINDE ON RECEPTACULITIDZ. 845 
RECEPTACULITES CALCIFERUS, Billings. 
1865. Receptaculites calciferus, Bill. Pal. Foss. Canada, vol. 1. 
p. 309, f. 346. 
The species is founded on a mere fragment, which shows the 
crossing ridges formed by the horizontal spicular rays. If Billings’s 
figure is correct, the rays and the spicular plates above them must 
be considerably larger than in &. occidentalis. 
Dstribution.—Calciferous formation: Mingan Islands, Lower 
St. Lawrence. 
REcEPTACULITES ARcriIcUS, Etheridge. 
1878. Receptaculites arcticus, Eth. Quart. Journ. Geol. Soe. 
vol. xxiv. p. 576. 
1882. Receptaculites arcticus, T. R. Jones, Cat. Foss. Foram. Brit. 
Mus. p. 3. 
The fragments of this species indicate flattened, platter-shaped 
individuals with slightly incurved margins. They were evidently 
of considerable size. The total thickness between the outer and 
Inner walls varies from 10 to 20 millim. The summit-plates reach 
to 7 millim. in width. No trace of the horizontal spicular rays can 
be seen; these and the head-plates are merged together into a layer 
of crystalline calcite 2-5 millim. in thickness. The vertical rays, 
like those of A. occidentalis, are contracted immediately beneath the 
horizontal rays and then expand again arid continue of an even thick- 
ness to their junction with the inner or upper plate. The rays are 
from 2°5 to 3°5 millim. in thickness, and their length corresponds 
to the thickness between the walls. The characters of the inner 
layer are not shown. ‘The structure is now entirely replaced by 
coarsely crystalline calcite. 
The large proportions of the form itself and of the spicular plates 
and rays distinguish this species from all others of the genus. 
Distribution.—Lower Silurian: Cape Louis Napoleon, Cape 
Frazer, Arctic regions (type specimens in British Museum). 
ReEcHpracurizEs ? CAaRBonaRIUs, F. Romer. 
1871. Receptaculites carbonarius, F. Romer, Jahresber. Schles. 
Gesellsch. p. 42. 
1880. Receptaculites carbonarius, F. Romer, Leth. Pal. 1 Th. 
peau, f. 53. 
The imperfect example of this species is insufficient to determine 
its originally complete form ; the author suggests that the relatively 
deep cup-shaped body may have been contracted above to a narrow 
aperture, in which case it would resemble an Jschadites. As, 
however, its interior characters are not known, its generic position 
remains doubtful. 
Distribution.—Carboniferous Limestone: Rothwaltersdorf, Silesia. 
RECEPTACULITES ? RHOMBIFER, I’. A. Romer. 
1850. Receptaculites | rhombifer, F. A. Romer, Paleeontographica, 
Spheeronites Badin prot tet. Jie 
