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Seven specimens were collected at Port Darwin at 12 fms (including
both sexes) ; two or three are females with ova. In the
last collection from H.M.S. ‘ xilert ’ specimens from Singapore
are apparently not specifically distinguishable, although presenting
some slight distinctions.
From Gebiopsis nitidus, A. M.-Edwards *, from the Cape Verds
(the type of the genus), this species is distinguished by the somewhat
different form of the rostrum, the existence of a spine on the
carpus of the chelipedes, the much shorter antennulary and antennal
peduncles, &c.
A male from Fremantle, S.AV. Australia (Dr. J . S. BoiverbanJc),
difiers in the form of the rostrum, which is anteriorly defiexed ; its
margins armed with ten spines in front of the first of the denticnles
of the sides of the head ; of these, four (of which two are longer) are
arranged in a semicircle iu front, and three, posterior to them, on
each side. I would propose to designate this, if specifically distinct,
G. howerbanlcii.
The genus Gebiopsis scarcely differs from Gebia, except in the
greater development of the lower finger of the chelipedes (which
thus are perfectly chelate), and is probably to he regarded as a subgenus.
3. Axius plectrorhynchus, Strahl.
I am somewhat uncertain of the identity of the specimen in the
‘ Alert ’ collection with Strahl’s type from Luzon, and therefore
subjoin the following description :—
The carapace and postahdomen are somev'hat membranaceous in
texture, as iu most species of the genus. The céphalothorax is vertically
deep and lateraUy compressed ; the carapace is smooth,
Avithout spines, and has the cervical suture distinctly marked. The
rostrum is prominent and narrow, concave above between the eyes ;
it is produced somewhat behiud them, and is armed on the lateral
margins with five or six teeth ; at the base of the rostrum, in the
median dorsal line, the carapace rises into an abrupt prominence ;
both the gastric and cardiac regions are distinctly defined. The
postahdominal segments are smooth, the first very small, the rest
nearly of equal length ; the lateral margins of the second to sixth
segments are nearly straight, entire, and are not produced into spines
at either the antero-lateral or postero-lateral angles ; the terminal
segment is quadrate, very little broader than long, a little broader
iu its proximal than in its distal half, and has its posterior margin
straight. The eyes are of moderate length and thickness, and have
distinct black corneæ ; the antennules are of moderate length, their
antepenultimate joints longer than the two following, which are
subequal ; the two flagella are of equal thickness, with naked joints.
The antennæ are shorter than the animal, the antepenultimate joint
of the peduncle shorter than the following, and armed beneath with
a small spinule ; the penultimate joint longer than the last joint ; the
* Nouv. Archiv. Mus. Hist. Nat. iv. p. 63, pi. xviii. figs. 4-7 (1868).
joints of the flageUa almost naked. The scale a t base of the antennas
is acuminate at its distal end, and between it and the peduncle
is a strong spine, which is apparently articulated with the antepenultimate
peduncular joint. The outer maxillipedes are suhpedi-
form, and the joints are hairy on their inner margins. The anterior
legs are wauting in the single specimen I have se en ; the three
following legs have the joints somewhat compressed ; the merus and
carpus iu the second legs are somewhat dilated and fringed below
with long hairs, the palm forming Avith the dactyl a perfect chela,
the fingers of AA+ich are acute and meet along the inner edges ;
the following legs are not subchelate ; the palm in the third pair
is ovate, fringed with short stiff hairs below and on the sides,
dactyl very short ; in the fourth pair the palm is somewhat slenderer
and more elongated, more thickly clothed towards its distal
end with plumose hairs ; the fifth legs are shorter and comparatively
slender and feeble. The postahdominal appendages are hirámose,
the inner larger than the outer branch. The rami of the uropoda
are somewhat indurated and considerably dilated ; their distal margins
are straight, ciliated, and minutely spinulose, aud they reach
to the end of the terminal segment of the postabdomen. Colour
(in spirit) whitish. Length about I inch 4^ lines (35 millim.).
The single example collected, which is, I think, a male, AA^as obtained
on the beach between tide-marks at Port Molle (Xo. 103),
and is in very imperfect condition.
Although the anterior legs are wanting in this specimen, there can,
I think, be no doubt of its generic position.
4. Tbalassina anomala (Herhst).
To this species probably belongs a female of rather small size
from Thursday Island, obtained in the mangrove-SAvamps (Xo. 124).
In this specimen the chelipedes are of nearly equal size, and both
chelæ are as slender and as much elongated as is the smaller chela
in the adult T. anomala, and are strongly spinulose on their upper
maaxr ggiiinios..
The examination of this specimen induces me to regard certain small
examples (of both sexes) from Borneo, Singapore, and the Indian
Ocean which I formerly * referred to T. anomala, and Avhich have
a more broadly triangulate rostrum, and the upper margins of the
wrists and hands of the chelipedes armed with much smaller spinules
along their upper margins, as probably referable to a distinct species.
AA*hite’s T. talpa, however, is, as I have already stated, probably a
young T. anomala.
To the localities mentioned in my paper referred to above is to he
added Xicol Bay, X.AA*. Australia, whence the Museum possesses a
small mutilated example (AI. du Boulay).
Perhaps the species described by Hess t from Sydney as T. maxima
is to he regarded merely as a variety of T. anomala.
* Ann. & Mag. Nat. Hist. ser. 5, v. p. 377 (1880).
t Archiv f. Naturgeschichte, xxxi. p. 163, pi. vii. fig. 18 (1865).
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