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628 C O L L E C T IO N S P R O M T H E W E S T E E N I N D I A N O C E A N .
CALCAREA.
No Calcarea from this district are recorded in Häckel’s ‘ Kalk-
schwiimme’ (1872); hut Schuffner (Jenaisch. Zeitsch. xi.) in 1878
described several species from Mauritius, where tbey were collected
by Prof. Möbius.
LEUCONIDÆ.
Two very widely distributed known species, a second species
added to a hitherto monotypic genus (Leucortis), and a known
Mascarcno species, all belonging to tbe Leuconida?, represent in this
collection tbo Calcarea of tbe Western part of tbe Indian Ocean.
53. Leucetta primigenia, var. megalirrbaphis.
Leucetta primigenia, var. megarapbis, Häckel, Kalkschwämme, ii.
p. 118.
Two subglobular specimens 9 and 18 millim. in diameter, respectively,
of tbe Dyssycus-iovm. Colour in spirit pale brown.
Häckel states tb at tbis variety is rare, but does not give localities.
Ill the specimen which I examined, tbe smaU triradiates aro chiefly
confined to a thin cortical layer.
Hab. SeycbeUe Islands, 12 fms.
Distribution o f species. Almost cosmopolitan.
54. Leucaltis bathybia, Häckel, var. mascarenica, nov.
( P l a t e LIV. figs. a, a'.)
Kalkschwamme, ii. p. 156, pi. xxviii. fig. 2.
Some specimens of tbe Amphoriscus-iorm, composed of branching
and anastomosing tubes, cylindrical or somewhat compressed, 2-5
to 3-5 millim. in diameter; lumen 1-5 to 2-5 millim. wide, wall
about -5 miUim. thick. Colour dull umber-brown to cream-colour.
Tbe large quadriradiates are very large, viz. rays about -07 millim.
thick, and ratber short, with a long apical ray projecting into tbe
cloacal cavity, and frequently a basal in tbe same plane but opposite
to the apical; tbe small triradiates and quadriradiates are very small,
viz. rays about -007 millim. tbick, and most commonly have the
forms figured in figs. 2 c, 2 cl of Häckel’s plate (I. c.), viz. with very
large facial angle. Tbe larger triradiates are usually regular, and
tbeir rays are about -04 millim. in diameter. The slight tbickness
of tbe body-waU, tbe proportions of the spicules, and the general
form of the specimens (which is simply cylindrical in Hackel’s
specimens) distinguish tbis form from varr. perimina and arahica,
Häckel; but in tbe straight or but slightly curved spicular rays it
approaches most closely tbe latter variety.
Hah. Darros Island, Amirante group; SeycbeUe Islands, 4 -1 2 fms.
Distribution of sqoedes. Red Sea (Hdckel); Port Jackson (Part I.,
p. 482, of tbis Eeport).
i
s p o n g i i d a . 629
55. Leucortis anguinea *.
( P l a t e L I II . fig. L ; P l a t e LIV. figs. d, d’.)
Erect, branched; stem and branches cylindrical, tubular. (Vent
opening probably at end of tube and nearly as wide as tube.)
Branches given off at angle of about 140° with each otber. WaU
•25 to -35 millim. tbick ; lumen of tube ^8 to 1'2 millim. in diameter.
Outer and inner surfaces even, smooth. Consistence in spirit elastic,
compressible (colour probably white or grey naturally, at present
pale purple, probably derived from otber sponges). Skeleton mainly
composed of triradiate spicules ; those (1) of outer surface sagittal,
with large facial angle, viz. 150° to 170°, the distal three fourths of
tbe lateral rays being, in tbe latter case, bent back so as to be
nearly in a line witb each otber ; basal ray about -28 millim. long,
laterals -16 to -22, diameter of rays at base ‘013 to -019 miUim.
Surface triradiates occasionaUy provided with a short stout apical
ray. (2) Triradiates of inner and central part of wall either
sagittal, witb facial angle of about 140°, tbe rays as in tbe surface-
spicules, or subregular, tbe angles being about 120° each and tbe
lateral rays slightly unequal ; in botb cases tbe lengths and diameters
of tbe rays as in tbe surface-spicules. Rays of triradiates, except
in tbe case above mentioned, almost straight, tapering from base to
point. (3) Linear spicules of general body-waU, stout, fusiform,
acerate, slightly curved, tapering equally to similarly sharp points
at botb ends; s iz e -65 by -032 milbm.; scattered singly at right
angles to surface, points not projecting except at peristome slightly.
(4) Fine acerate ? of peristome, length probably about -22 millim.,
thickness -0032 millim. ; closely aggregated a t outer surface, a t right
angles to surface (tbe inner end is sbarp, the outer end has not been
observed). Canals leading from cloacal cavity small ; chambers of
canal-system small, inconspicuous. Spicules of centre of wall densely
aggregated.
Hah. Providence Reef, Mascarene group, 24 fms. ; bottom, sand
and dead coral.
A single specimen, imperfect at both extremities, represents the
species. I t is 25 miRim. in height, and consists of a short common
stem and of two branches, little inferior to tbe stem in diameter, one
of tbem even increasing in diameter towards its termination.
Erom tbe occurrence of tbe fine linear spicules in some of the first
sections which were made it is inferred tb at tbey were from a peristome,
which was probably almost as wide as tbe tube and bad a
slight fringe. The occurrence of a few quadriradiates bas been
observed also in tbe only species assigned by Häckel to tbe genus,
viz. L .p u lv in a r, Häckel; and tbus, if HäckeTs terms were employed,
this specimen would be distinguishable as a “ connecting
varietv ” under the name Leucandra anguineus. This species is
markedly distinct from L. pulvinar in its slender form, in tbe
relatively smaU size of tbe acerate spicules of tbe body-wall, and in
* Anguineus, snake-like, from the elongate pliable character of the specimens.
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