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380 COLLECTIONS FEOM MELANESIA.
millim. respectively ; the vertical height, viz. to base of uppermost
tube, is 30 millim. The surface is darkish umber-brown iu colour,
that of the body has a slightly irregularly wrinkled parchment-like
appearance, th at of the tubes is somewhat wrinkled in the direction
of their length, and one of them presents further a somewhat
shagreen-like surface, as if beset with very short connli (scarcely 1
millim. high). On dissection it is found th at whereas the tubes are
chiefly (in the dry state) composed of a horny skeleton, 1-2 millim.
thick, the body is a very cavernous mass whose hulk is largely
occupied by large canals or chambers, 7-10 millim. wide, opening
directly into the bases of the similarly wide tubes, the skeleton of
the body thus consisting of trabeeulæ with smooth, rounded surfaces ;
the subglobular appearance of the body is produced by the bridging
over of tho spaces between these trabeeulæ by a brown paper-like
membrane, which is found on microscopic examination to contain
no horny elements, but may or may not enclose a certain quantity
of minute foreign bodies (sponge-spicules, &c.).
Examining the skeleton of the body with the microscope, I find
from vertical sections that it consists of a close reticulation of solid
cylindrical horny fibres, distinguishable as :— (1) primary, stouter,
approximately straight and parallel to each other, about •07-'04
millim. apart, more or less vertical to the surface, according to
position, thickness about -03--04 millim. ; and (2) secondary, similar
to primary, and more or less vertical to them, but often very obliquely
placed, thickness about -OIB-Od millim.; distance apart very
variable, from -14 millim. upwards. Colour of fibre, pale to medium
amber-colour. Although single primary fibres do not appear to
project in the way strikingly exhibited in the more typical forms of
Euspongia officinalis, where they project well above the general surface,
and where distinct “ connli ” are formed by the dermis around
their bases, yet the sections show an aggregation and projection of
the general skeleton at certain points, apparently representing connli,
but not (in the present state of the sponge) finding expression on
the outer surface in the conical eminences which usually occur here
in Euspongia. On the tubes the dermis (immediately below a membranous
substance containing a few foreign bodies) is formed by
a very close and regular horny network, composed of primary
and secondary fibres, like the main skeleton, hut arranged parallel,
instead of vertically, to the surface. The proportions of the fibres
are about the same, respectively, as those of the main skeleton, but
the primaries are only -03--1 millim. apart. All the skeleton-
fibres are devoid of sand-core, but are coated (in parts strongly) by
the minute strongly refractive brown globules which Prof. É. E.
Schulze has considered to be probably of Cryptogamous affinities.
In two points is this sponge of especial interest, viz. (1) in the
almost complete subordination of the general arrangement of the
skeletal framework to the largely developed excretory canals ; (2)
in the almost total suppression of the “ connli.” A further point
is the absence of sand-cored fibres. I was at first inclined to separate
it generically from Euspongia, as having the large mæandrine
SPONGIIDA.
excretory chambers, separated by comparatively narrow and sheetlike
skeletal trabecula?, with even surfaces, which distinguish Hip-
pospongia; but on looking at the brief description given by Prof. F.
E. Schulze (Zeitsch. wiss. Zool. xxxii. p. 620) of the Adriatic form
which he has placed under Euspongia officinalis, as var. tubulosa,
I saw th at he had had a closely similar form before him. I t agrees
with pur specimen in the long tubes (of much less diameter, however,
in the Adriatic tubulosa than here) and in the absence of sand-
cored fibres; but it appears to want the following striking peculiarities
of our form :—(1) suhglobular form (incrusting in Schulze’s
specimens); (2) trabecular structure of main body; (3) absence of
connli (they are stated by Schulze to occur on the general body of
the sponge, but in a very well-preserved specimen in absolute alcohol
which he has liberally presented to the National Collection, I find
them only on some small digitate lobes which spring from the body;
those possibly occurring upon one of the tubes in var. cavernosa are
evidently only exceptional) ; (4) approximate equality in stoutness
of^ fibres throughout (in var. tubulosa those near the surface are
said to be thinner than elsewhere).
In a preparation made from Prof. Schulze’s specimen I do not
notice a special thinness of the fibres at the surface, but they seem
to have a slightly greater diameter throughout than in our form.
Considering the dry state of this single specimen and the evident
plasticity of form in E. officinalis, I think it best to associate this
form provisionally with that termed by Prof. Schulze var. tubulosa,
feeling th a t it may he only a mere extreme variation of the species
in the same direction as th a t variety, deferring (as 1 feel bound to
do on a question which Prof. Schulze has made so eminently his
own) to Prof. Schulze’s judgment in specifically uniting aberrant
forms like these with those familiarly known as E. officinalis ; I am,
however, induced, from the points of divergence from tubulosa noted
above, to assign to it a distinct varietal designation.
Hab. Torres Straits, 10 fms.
Distribution (of species). Mediterranean (Schulze, &c.).
4. Euspongia septosa.
? Spongia septosa, Lamarck, Ann. Mus. Hist. Nat. xx. p. 373.
I t is possible th at Lamarck’s species, of which I have access to
the description only, is a Dench'ospongia (Hyatt), as its somewhat
honeycomb-like surface renders not impossible; but it seems to
resemble a species in this collection, represented by two small specimens
in spirit, of a dark grey colour, each attached to two or more
stones, over which they form horizontally expanded laminm which
rise into subcylindrical lobes 5 to 7 millim. in diameter. The surface
is broken up by a number of sharp prominent ridges and points
1 to 3 millim. h ig h ; the intermediate surface is rough. Primary
skeleton-fibres set approximately a t right angles to surface, thickness
about -06 millim.; secondaries approximately vertical to primaries,
about -035 to -053 millim. in thickness, forming with some connecting
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