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Sarcode-spicules :—(3) Tricurvate acerate, smooth, tapering gradually
to fine points; median curve rather sharp, forming angle
of about 150° ; from this point arms almost straight, until just
before tips, which turn up slightly ; size -19--22 by -006 millim.
(4) Equianchorate, navicular, shaft slender, smooth, curve gradual
and slight; palms narrow, viz, about -08 long b y -0055 miUim. broad,
tapering to sbarp points at apex, square below ; tubercle slight,
ratber elongate, length -022 millim.
Hah, Mozambique, between tide-marks.
Two specimens and a fragment are in tbe colleetion. Tbe largest
measures 110 millim. ( 4 | inches) in greatest height, 85 millim.
(32 inches) iu greatest lateral expansion ; common stem 55 millim.
long, 20 by 10 millim. in diameter at middle of its course, rather
tortuous, deeplj! scored on one side by a main median longitudinal
depression. The second specimen has its branches more cylindrical
than those of tbe larger specimen ; but it has grown abnormally, some
of tbe branches being twisted back, and anastomosis occurs near the
base of the specimen. Tbe description of Spongia palmata, Lamarck
(Ann. Mus. Hist. Nat. xx. p. 453), var. /3, recalls tbis sponge. Tbe
typical form of tbe species, which I bave seen at Paris, resembles it
more closely than does the specimen on which this var. ¡3 was probably
founded ; however, microscopic examination shows S. palmata
to be a Chalina. ^ While tbe present species resembles Desmacidon
fmticosa, Monti, in texture and in tbe structure of the skeleton, it
IS yet quite distinct on account of its solid branches, its acerate
skeleton- and its tricurvate (not bihamate) fiesh-spicules. D. arciferum,,
Schmidt (Algiers), appears to approach it the most nearly of
described species, but an acerate spicule is mentioned in addition to
tbe tricurvate. D.frondosum (Ehlers), Esper, from “ East Indies,”
reseinbles tbis sponge in general appearance, but bas echinating
spicules, some of wbicb are strongly spined, and no tricurvate is
mentioned ; hence it seems to be a Clathria.
31. lotrochota purpurea.
Halichondria purpurea, Bowerhank, P. Z. S. 1875, p. 293.
See Pa rt L, p. 434, of tbis Peport.
Fine specimens, cbiefly of the usual cylindrical form, and witb
the same coarsely roughened surface as in the Australian specimens
Like those specimens, too, tbey show a tendency to become flattened’
and to vary in colour from dark purple to dark green. Tbe spicii-’
lation is essentially the same as in the Australian specimens. Tbe
maximum height is also ju st tbe same, viz. 150 miUim. (6 inches).
nab. Etoile Island, Amirante group, 13 fms.
Distrihution. See P a rt I. p. 434.
32. lotrocbota haculifera.
See Pa rt I., p. 435, of tbis Report.
Some smaU specimens, in spirit and in the dry state. In the
S P O N G I I D A . 611
finely hispid surface and tbe low irregularly lobate form, together
with tbe spicular characters, tbey agree closely witb the Australian
specimen, but tbe average diameter of tbe lobes is somewhat less
(about 10 millim.).
Hab. Providence Peef, Mascarene Islands, 24 fms.
Distribution. Port Darwin.
33. Esperia gelatinosa. (Plate LIV. f ig s ./ - / '" .)
Low incrusting masses, frequently involving foreign bodies,
occasionaPy rising into slender lobes. Surface in spirit undulating’
glabrous. ^ Consistence tough, elastic, firm. Colour pale greenish
grey or pinkish brown ; general appearance gelatinous, semi-transparent.
Main skeleton ratber confused in the incrusting specimens ; tbe
vertical lines _ near tbe surface being short, broad, loose,’ and
closely approximated ; in thicker specimens tbe ordinary Esperian
distinct spiculo-fibres appear a t some distance below tbe surface ;
primaries crossed by more or less numerous detached skeleton^
spicules. Dermal skeleton composed of confusedly intercrossing
spicules not arranged into spiculo-fibrous reticulation. Sarcode very
pale yellow, transparent.
. Spicules (1) Skeleton subspinulate ; bead oval, slightly bnt
distinctly demarcated from sbaft, about two thirds the maximum
diameter of tbe latter ; shaft tapering ratber abruptly to sbarp
point ; size of spicule -5 by -016 millim. (2) Large inequianchorate ;
large end moderately broad, about half the total length of tbe spicule,
tubercle long, lower angles of outer palms slightly rounded ; smaU
end subtriangular, ratber small, pointed below, tubercle small,
tongue-shaped, a small reverted margin extending as far as the
tubercle in tbe middle ; size of spicule -06 by -0032 millim. (3) Small
inequianchorate, large end about three fifths the total length of
the spicule; sbaft and arms weU but graduaUy curved, tubercle
short ; lesser end very small, not prolonged below into a point; length
of spicule -019 millim. (4) Bihamate, contort, slender, well curved,
sharp-pointed ; size -057 by -002 millim. (5) Trichites in oblong
compact bundles about -02 millim. long and -0063 to -0075 millim.
in diameter ; spicules approximately straight. Extremely abundant.
Hab. Providence Reef and Providence Island, Mascarene group,
19-24 fms. ; bottom, sand or dead coral.
_ Tbe longest lobes are 20-30 millim. long and 3 -6 millim. in
diameter. In habit, spiculation, and arrangement of skeleton it
mucb resembles E. lævis. Carter (Ann. & Mag. N. H. 1882, ix. p. 291,
pi. xi. fig. 16), from Venezuela, aud E.pellucida, mibi (Part I., p. 437,’
of this Peport) ; but the small inequianchorate here bas not the
terminal point described by Carter, and the trichites are mucb
smaUer (-02 miUim. instead of -067 millim. long) ; from E.joellucida
it differs in tbe small, short, quadrangiUar triebite-bundles, in the
smaUer size of tbe anchorates, &e. The species is quite abundant,
though no large specimens were found.
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