274 COLLECTIONS FEOM MELANESIA.
with two or three strong triangular teeth on its inner margin ; palm
about as long as the wrist, and with the lower finger almost triangulate
in shape ; the outer surface of the palm is divided by four
sulci into five longitudinal, smooth, rounded ridges, including the
rather less prominent line or ridge along the lower margin of the
palm • the fingers are smooth, scarcely denticulated on their inner
margins, incurved at the tips, and have between them (when closed)
a more or less distinct h iatu s; the first to third ambulatory legs
have the joints (e.vcept the last) armed with small tubercles or
prominences on their upper margins ; the dactyli have several
spinules on their lower margins. The colour (of spint-specimens)
is white, faintly tinged or spotted with pink. Length 2g lines
(5 millim.) ; breadth a little over 2 | lines (nearly 6 millim.).
Two specimens (male and female) are in the first collection one
obtained at Port Molle, 5 -1 2 fms. (No. 118), and the other at
Albany Island, 3 -4 fms. In the second collection are eight specimens
(male and female) obtained at Thursday Island in 3 -4 fms.
(No. 177), 4 -5 fms. (No. 165). Air. Haswell records it also from
Holborn Island. • i
This species cannot be confounded with any ol the species oi
Pachycheles mentioned by Dr. Stimpson in his very useful Synopsis
of the Anomura * ; and in its slenderer chelipedes approaches Por-
cellana, to which genus Mr. Haswell refers it.
Tn two specimens from Prince of Wales Channel, 7 fms. (N os.
142 169), which are probably not distinct, the chelipedes are more
unequal and smoother. One example has the left chelipede much
enlarged, the ridges on the palm separated by wide interspaces, and
the fingers strongly arcuated.
18 Porcellana nitida, Haswell, var. rotundifrons,
( P l a t e XXX. fig. E.)
Carapace smooth, shining, everywhere striated ; the striæ short
and interrupted. The front is rather prominent, transverse, aud
very obscurely 3-lobed; the median lobe very broad and rounded ;
the lateral lobes (or inner orbital angles) also rounded and small.
Behind the outer orbital angle, which is dentiform, is a second acute
tooth and behind this a rounded prominence ; there is a small tooth
on the suhhepatic region. The basal joint of the antennæ is vep^
short the second and third longer, and the fourth very short ; the
flagellum naked; the ischium-joint of the outer maxillipedes has a
spine on its outer margin ; the inner margin of the_ merus is R e duced
into a thin lobe at base, the foUowing joint is robust. The
chelipedes are robust and elongated, the joints are smooth; the
arm and wrist have their inner margins cristiform and acute and
entire • the arm is very short, the wrist somewhat longer ; the
larger ’palm (in an adult male) is robust and considerably elongated,
its upper margin rounded ; the fingers are shorter than the palm,
* Proc. Acad. Nat. Sci. Philad. p. 225 (1858).
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curved at tips, and having between them a smaU hiatus when
closed ; the upper or mobile finger is strongly arcuated, sometimes
with a strong blunt tooth at base ; the lower has its inner margin
obscurely crenulated and sometimes toothed. The first three pairs
of ambulatory legs are robust, the joints nearly naked and without
denticles or spinules, except on the inferior margins of the penultimate
joints, which have two or three spinules at or near the distal
extremity ; the dactyli are short, robust, and appear biunguiculate
on account of the considerable development of tho accessory spine on
the inferior margin, behind which is another small denticle. The
ground-colour (in spirit) is yellowish ; the carapace and chelipedes
are blotched with pink or marked with irregular lines of the same
colour. Length of carapace of an adult male about 4 lines ( 8 |
millim.), breadth about 3 | lines (8 millim.) ; length of chelipede,
Avhen fully extended, about 8g lines (20 millim.).
Port Denison, 4 fms. (No. 122) : a considerable number of specimens
were obtained. Specimens were also received with the
second collection from Lriday Island, 10 fms. (No. 153), Dundas
Straits, 17 fms. (No. 161), Port Darwin, 12 fms., and others dredged
in the Arafura Sea at 32-36 fms. (No. 160).
The description, except as regards coloration, is taken from an
adult male ; the coloration is perfectly preserved in one specimen
only, a female with ova. The larger specimens possessing both
chelipedes are mostly of the female sex. In the females and
smaller-sized specimens the lateral lobes of the front are often more
acute, the palms of the chelipedes relatively shorter, the fingers
meet along their inner edges when closed, and the upper finger has
not the strong tooth at base, &c.
In the robust and biunguiculate dactyli of the ambulatory legs
this form resembles the species of Polyonyx, but differs in the relatively
longer carapace, which resembles th a t of other species of
Porcellana.
I refer it doubtfully to P. nitida*, which is very briefly described,
and differs apparently in the triangulate form of the
median frontal lobe, and in having an additional lateral marginal
spine behind the outer angle of the orhit ; hut as Haswell’s types
were from Port Denison, at which locality specimens of the form
now described were taken by Dr. Coppinger, I distinguish it merely
as a variety.
19. Porcellana dispar, Stimpson. ( P l a t e XXX. fig. C.)
Pour males and two females from Port Jackson, 5—7 fms. (No.
104), are referred to this species, which Air. Haswell (Oat. p. 149)
observes is very common at this locality. He also records it from
Port Stephens.
Stimpson’s description agrees very well with the adult males, hut
* Vide Haswell, Catalogue, p. 148 (1882).
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