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71. Esperia obscura.
? Carter, Ann. 4' Mag. Nat. Hist. 1882, ix. p. 299, pi. xi._ fig. 18.
? Mycale grandis, Gray, P. Z. 8. 1807, p. 633=:“ pline indische Es-
pene,” Schmidt, Suppl. Spong. Adr. Meer. p. 34, pi, in. fig. 11.
Mr. Carter assigned the above name to a massive specimen from
Ereemantle, S.W. Australia, of which he says {I. c.) it has ‘‘ all^ the
characters of Esperia, viz. lacc-like dermal layer, rigid interior fibre,
and acuate (sub-pinlike) form of skeletal spicide, bnt with an inequianchorate
about 5-6000ths ” (of an inch) “ long so transparent in
its detail th a t all I can give of it are the representations (pi. xi.
fig. 18), in the hope th at it might be thus recognized and finally
illustrated.” In the present collection made by H.M.S. ‘ Alert ’
occur two small imperfect specimens of an Esperia which has (besides
a larger one) a small inequianchorate spicule which strongly resemblps
Mr. Carter’s figures above referred to, and does not contradict in
any point the other parts of the short description which was all
th at Mr. Carter was able to give of his species. I therefore propose
to refer the present specimens to th at species provisionally
until other specimens are obtained from Ereemantle or its neigh-
hourhood which may clear up the question of identity. The following
is a description of the ‘ Alert ’ species ; it may be taken as characteristic,
so far as the more minute characters go, tho tissues being
in a good state of preservation :—
Sponge massive, enclosing detached (and perhaps fixed) foreign
bodies. Texture firm, rather brittle. Surface gently undulating,
glabrous. Yents numerous, oval, 1 to 2-5 millim. in greatest diameter,
scattered on general surface ; margins thin, sometimes projecting
somewhat; main excretory canals rising from a distance
below the surface. Dermal membrane thin, glabrous, semitransparent,
firm. Colour in spirit pale dull brown.
Main skeleton—spiculo-fibre moderately wcU defined, delicate,
branching at various angles, from 5 to 10 spicules broad. Dermal
skeleton diffuse, the spicules scarcely ever arranged into definite
tracts, hut loosely matted. Sarcode thin, very pale yellow-hrown,
slightly granular.
Spicules :—(1) Skeleton subspinulate, straight or slightly curved,
head elongate, suhterminal, slight, graduaUy passing into a hluntly-
rounded narrower extremity on the one hand, and into the shaft on
the other ; diameter of head decidedly less than th at of sh a ft; shaft
tapering graduaUy to within about three diameters of apex and then
rapidly to a sharp point; size’8 by -014 millim. (2) Large inequianchorate
; shaft slightly curved, s to u t; larger end of spicule of same
longitudinal and horizontal diameter, viz. one third as much as total
length of spicule; lateral palms finely curved, ending below in
sharp inwardly-curved points and reduced to narrow falciform processes
with a narrow reverted rim as seen from fro n t; anterior palm
oblong, with rounded angles as seen from fro n t; tubercle distinct,
o v a l; smaUer end of spicule with abrupt square upper margin ;
S P O N G I I D A . 439
lateral margins reverted at upper end; tubercle strong, oval; breadth
. and length of small end about half those of larger e n d ; length of
spicule -12 millim. (3) SmaU inequianchorate ; shaft slender, sharply
bent at about middle ; larger end about three fourths of total length
ot spicule in length and about half th at amount in breadth ; the lateral
arms as seen from front finelj» curved and forming long wing-like
processes, pointed below and excavated on their inferior and inner
aspects, reaching almost to the upper edge of the smaller end of the
siucule ; their curve coincides with th at of the lower e n d ; smaUer
end like th at of the large inequianchorate, hut truncate at its distal
; length of spicule '032 millim. (4) Bihamate, contort,
slender, curve_ wide, points sharp; size -057 by -0032 millim.
(5) Trichites, in sheaves of 10 to 20 or 3 0 ; finely pointed, apparently
straight, each about ’032 long by •0016 millim. thick ; very
abundant in some parts of dermal membrane.
Hah. ihursday Island, Torres Straits, 4 -6 fms. ; bottom rock and
sand.
Distrihution. Ereemantle, S.W. Australia (Carter)"!; Indian
Ocean {Schmidt)"!
The larger piece is 43 millim. ( 1 | inch) long, by 20 millim. ( | inch)
broad, by 10 millim. thick; it is uncertain whether it ever had an
independent stem or whether it depended for attachment on the fragments
of shells (fee. which it involves in its substance, or on fixed
foreign bodies ; the smaUer piece is similar in its relations, and
perhaps both originally formed p art of one specimen.
The large anchorate strongly resembles th at figured by Schmidt
{I. c. supra) as belonging to “ eine indische Esperie,” named Mycale
grandis by Gray (I.e.), in tho form of its larger end, although the
anterior palm is relatively larger than in th at form, while the middle
palm of the lower end is far smaUer relatively to the spicule and
to the_ lateral palms than in Schmidt’s anchorate; but it seems likely
from its appearance th at the lower end of the spicule was imperfectly
developed in the example figured by Schmidt. The spicule
was even larger than th at of our species, viz. -145 millim. long,
according to Schmidt’s measurement. Gray’s species is based simply
on th a t author’s description of the spicule.
PHORIOSPONGIA.
Marshall, Zeitschr. wiss. Zool. xxxv. p. 122.
The striking structural character on which this genus was
founded receives confirmation and illustration from the following
species; I have referred to it as occurring in Clathria {MicrocioncC
tuherosa, Bowerbank (see p. 444). Fibularia anchorata. Carter fron
Antigua (Ann. & Mag. N. H. 1882, ix. p. 283), is perhaps a Phor
spongia.
72. Phoriospongia fibrosa. (P la te XL II. fig. g.)
Massive, sessile, irregularly shaped; surface uneven, with irregular
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