802 DR, G. J. HINDE ON RECEPTACULITID®. 
columns of the interior of the organism, now uniformly filled with 
matrix, were, in the lifetime of the animal, occupied by sarcode. 
He further believes that the original material of the skeleton was a 
finely fibrous crystalline aragonite, and that this structure was 
entirely opposed to the probability of its alliance to sponges. On 
the other hand, the inner organization agrees very well with that 
of the Foraminifera, with which order Receptaculites may unquestion- 
ably be placed, though its relationships are not with the Orbitolitide, 
as Salter first, and Dames afterwards, supposed, but with the 
family of the Dactyloporide. As the result of an examination of 
specimens of [schadites Kenigi from the Silurian of the isle of Got- 
land, Gumbel concludes that its organization does not in the least 
differ from that of Receptaculites, so that there is no ground for 
constituting it a distinct species ; and Yetragonis only differs in the 
accidental absence, through weathering, of the plates of the outer 
surface. Still further, Gumbel finds a relationship between Proto- 
spongia fenestrata, Salt., and Leceptaculites. 
In 1878, Mr. R. Etheridge, F.R.S., described, in the Quart. 
Journ. Geol. Soc. vol. xxxiv. p. 575, from Silurian strata in the 
Arctic Regions, two species of Receptaculites, one of which is referred 
to R. occidentalis, and the other, which is the largest species yet 
known, is named R. arcticus. 
Quenstedt, in the ‘ Petrefactenkunde Deutschlands,’ Bd. 5 (1878), — 
p. 586, states that though the characters of Receptaculites are not 
yet well understood, it may nevertheless belong to the corals. The 
author figures, as a new species, 2. scyphiordes, a cup-shaped speci- 
men from Devonian strata at Ober-Kunzendorf in Silesia, without, 
however, indicating any characters which could distinguish it from 
R. Neptun. Other species of Receptaculites are figured, and the 
characters of Ischadites and Tetragonis are referred to, without, 
however, adding anything of importance respecting these genera. 
Ferd. Romer, in the ‘ Lethea Paleozoica,’ 1 Th. (1880), p. 285, 
proposes to include in the family of the Receptaculitide the gencra 
Receptaculites, Cyclocrinus, Pasceolus, .Tetragonis, Polygonospheris, 
and Archeocyathus, and places the family provisionally with the 
Foraminifera, although there is no satisfactory ground for a com- 
parison with that group. He adopts the description of the structure 
of Receptaculites given by Giimbel, and agrees with this author that 
there are no apertures in the plates of the inner surface as described 
by Billings; but he does not think that there is any communication 
between the margins of the plates as surmised by Gumbel. Romer 
further adds a description and figure of a new species, Receptaculites 
carbonarius, from the Carboniferous Limestone of Silesia. With 
respect to Ischadites, Romer thinks that this genus, if not identical 
with Receptaculites, stands very near to it. Bohemian specimens 
usually referred to I. Kamnigii, are, according to Romer, distinct 
from this species, probably belonging to a different genus. The term 
Polygonospherites is employed instead of Spherospongia, Pengelly, as 
the author thinks that this latter term should be rejected, since it 
implies a connexion with sponges. Romer regards the relationship 
between Spherospongia tessellata, Phill., sp., and Receptaculites as 
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