1862. ] DR. J. E. GRAY ON SOME NEW ZOOPHYTES. 35 
This genus seems to form a particular group of the Aleyonaires, 
which may be called after this genus Solenocaulonide, characterized 
by the tubular form of the axis, the tubes being formed of a thin 
coriaceous substance. The smaller branches are subsolid and cel- 
lular within, but they soon become hollow. It has been said that 
the tubular form arises from the abortion of the epithelic tissue of 
the centre of the axis. This may be true if we can regard the large 
lax cells in the interior of the young branchlet as epithelic tissue ; 
but the imner surface of the tube of the axis is quite smooth and 
simple, and the branchlets never become large like the main stem. 
This coral cannot be considered as a solid stem becoming hollow, 
as the last-formed (younger) parts at the end of the branches are in 
the form of a foliaceous expansion, which gradually folds up toge- 
ther on itself, coalesces, and forms a tube nearly of the same dia- 
meter as the main stem. The large apertures which occur in the 
stem and base of the branches, and communicate with the central 
cavity, are the parts of the expanded lamina which have not been 
closed in when the other portions of the tube were formed. 
The specimen described evidently grew in a nearly horizontal po- 
sition ; for one side of the main stem and branches is entirely without 
any cells, and the branchlets on the same side are fewer than on the 
other, showing that this part was beneath, and not exposed to the 
light. Ido not give this as the generic or specific character, as it 
may be only incidental to the specimen—a fact that can only be 
determined by the examination of a larger number of examples. 
Mr. Holdsworth has suggested that it may be the same as or allied to 
Gorgonia trichostemma of Dana (Zoophytes, 665, t. 59. f. 3); but 
Dana does not describe the main stem as tubular. But the coral is, 
like many others in his work, so badly figured and described that it 
is impossible to determine with any certainty what it is intended to 
represent.. Milne-Edwards seems to have been equally doubtful (see 
Coralliaires, i. 154) as to its affinities. 
The genus Celogorgia of Milne-Edwards (Coralliaires, vol. i. 
p- 191) should be placed in the same family. It is described as 
arborescent, very branching, and with slender cylindrical branches 
with scattered, subcylindrical, elongate polype-cells. Only one spe- 
cies is known, viz. G. palmosa, from Zanzibar. 
Among the specimens preserved in spirits in the same collection 
there is also a new form of dleyon, which seems to me to be a type 
of a new genus allied to Xenia, but quite distinct from it both in the 
form of the cells and in the polypes being completely retractile. It 
has some characters in common with my genus Nidalia, described 
in the ‘Proceedings of the Zoological Society,’ 1835, p. 6, and 
figured, Radiata, Pl. III. fig. 2, but differs from it in the surface of 
the coral being minutely granular, and not spiculose. 
BELLONELLA. 
Coral cylindrical, formed of a number of subcylindrical tubes ag- 
glutinated together and forming at the top a hemispherical head of 
subcylindrical prominent cells, which are angular at the tip. The 
