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242 COLLECTIONS FROM MELANESIA.
86. Pseudorhombila sulcatifrons (Stimpson), var. australiensis.
(P late XXIV. fig. C.)
As this variety may prove to he specifically distinct, I subjoin the
following description :—
As in Heteroplax dentata, Stimpson, the carapace is slightly tran sverse,
anteriorly somewhat defiexed, posteriorly plane ; it attains its
greatest width at the third lateral tooth. The front is about half
the width of the carapace ; its anterior margin is faintly transversely
sulcated, without any median fissure, aud is s tra ig h t; there is, however,
a small notch on each side close to the lateral angles, which
thus are separated as small teeth. The antero-lateral margins of
the carapace are much shorter than the postero-lateral and armed
with four teeth (the enter orbital angle included) ; the third tooth
is larger and more prominent than the others, the fourth the
smallest; there is a small median notch in the middle of the upper
orbital margin; slight transverse inequalities are apparent on the
front of the gastric region and on the sides of the carapace near the
lateral teeth. The postahdomen is triangulate, with the segments
distinct, the penultimate and the last being the longest; the second
segment covers the whole width of the sternum and reaches to the
bases of the fifth legs. The eyes are placed upon rather short thick
pedicels. The antennules are rather long and transversely folded.
The basal antennal joint is slender, and although longer than either
of the following joints, does not reach to the frontal margin ; the
flagellum is elongated. Scarcely any traces are visible of palatal
ridges. The merus-joint of the maxillipedes is quadrate, and much
shorter than the preceding ; the next joint is articulated with it at
its antero-internal angle. The chelipedes are of nearly equal size ;
merus trigonous, short, with a tooth near the distal end of its upper
m arg in ; carpus smooth externally, with a spiniform tooth on its
inner margin ; palm smooth externally, moderately convex; fingers
about as long as the palm, denticulated on their inner margins and
having between them scarcelj^ any interspace when closed. Ambulatory
legs rather long, with the joints very slender, unarmed; the
last three with their margins somewhat scantily pubescent. Length
of carapace nearly 3 lines (6 millim.), breadth nearly 4 lines
(8 millim.) ; length of ambulatory leg of third pair about 6 | lines
(14 millim.).
The single specimen was obtained at Port Alolle, 14 fms. (Xo. 93),
and is apparently a female, although possessing an unusually narrow
postahdomen. I t difiers from Heteroplax dentata and H. transversa,
Stimpson*, in having the second tooth of the antero-lateral
margins as long as the preceding, and also, it would appear, the
shorter thicker eye-peduncles, and from the latter also in the
narrower carapace. From the typical P. sulcatifrons (Stimpson),
from Hong-Kong, it is distinguished only by the non-emarginate
* Proc. Acad. Nat. Sci. Philad. p. 94 (1858).
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CRUSTACEA. 243
front and the absence of the woolly patch on the outer surface of the
^""iitocheira bispinosa, Kinahan, from Port Phillip*, which in m a n y
of its characters seems to be allied to Pseudorhombila sulcatifrons, is
at once distinguished by having but a single spine behind the exterior
orbital angle. Specimens are in the British-AIuseum collection from
Port Curtis (H.M.S. ‘ Herald j . Mr. Haswell, in his Catalogue,
omits reference to this species, and to several others described by
Kinahan. ^ i. i
The species described by Haswell as Eucrate affinis (Catalogue,
p 86) is, I think, identical with typical P. sulcatijrons (Stimpson).
The type was from Holborn Island, near Port Denison (20 fms.).
I have quite recently described, under the name P. sulcatifrons
var atlanticaf, a specimen from Horee Island, Senegambia, which
is scarcely distinguishable from Oriental examples of this species.
87. Ceratoplax arciiata. (P late XXV. fig. B.)
Carapace longitudinally convex, scarcely broader than long and
not wider behind than in the middle; the surface, when viewed
under a lens of sufficient power, is seen to he covered with a very
short pubescence; the sides are anteriorly arcuated, posteriorly
p a ra lle l: the antero-lateral margins, which are acute, are divided by
three slight notches, but can scarcely he described as dentated. Ih e
front forms with the antero-lateral margins a continnous curved
line ; it is somewhat deflexed, obscurely sinuated in the middle, with
the exterior angles rounded off and not prominent, and has some
longer hairs on its upper surface. The first two segments of the
postahdomen in tho male are very much shorter than the following
almost transversely linear in shape; the first segment, although
laterallv produced, does not reach to the bases of-the fifth ambulatory
legs The eye-peduncles fit closely into the orbits (which are not
deep) and have their anterior and upper margins acute and clothed
with rather long h a irs ; the small cornese are lateral, and are visible
only in an inferior view. The epistoma is transversely linear ; the
antennules transversely plicated; the basal (or reaUecond) antennal
joint is slender, and does not nearly reach to the inferior margin of
the front (see fig. 5); the flagellum is of moderate length There
are no distinct palatal ridges. The outer maxillipedes are broad in
proportion to their length ; the ischium-joint little broader than
long; the merns transverse, its extero-dorsal angle prominent. Ih e
chelipedes are moderately large, the right a little the larger, and the
margins of the joints are for the most part clothed with rather long
h a irs; the carpus or wrist is angnlated on its inner surface with
some long hairs at the angle ; the palm is little longer than broad,
and vertically deepest at the place of articulation with the mobile
finger, its margins are not cristated, its outer surface smooth and
^ Journ. Roy. Dublin Soc. i. p. 121, pi. iii. « g ; (1858)-
t Fide Ann. & Mag. Nat. Hist. ser. o, vm. p. 259 (1881).
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