THE GREAT WARTY CRAB

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additions to the type species Eurynome aspera (Pennant), for though the names scutellata and boletifera have been given to forms taken in the Mediterranean, it is probable that they are not distinct from, or at most are only varieties of, the species found on the British coasts. It is, as might be guessed from the names, a species rough with warts or tubercles. The walking-legs are short, but the chelipeds in the male are elongate, being nearly twice the length of the body according to Bell, but according to Leach three times its length. Eurynome tenuicornis, Malm, from Bohuslän, Guilmarsfjord, is there found together with Eurynome aspera.

Partherope, Fabricius, 1798, has in its type species, Parthenope horrida (Linn.), an animal of truly remarkable appearance. It is recorded from the West and East Indies, and has been called the great Warty Crab or stigmatised as the Lazy Crab. Its carapace is pentagonal, broader than long. While this and the legs are covered with warts and spines, the pleon is said to be full of pits, almost as if eaten through. The chelipeds are large and long. From the picture of it given by Herbst one might suppose that it was intended to look like a piece of light-red sandstone overgrown here and there with green algæ.

Lambrus, Leach, 1815, unlike the two preceding genera, suffers from no paucity of species. So numerous indeed are they that in 1878 Professor A. Milne-Edwards deemed it expedient to subdivide Lambrus into ten genera, including in the number Solenolambrus, Stimpson, and Mesorhoea, Stimpson. The species are distributed over all the warmer seas of the world, and some occur in the Mediterranean. Of these Lambrus macrochēlos (Herbst), meaning the Lambrus with long chelipeds, justifies its name, but almost puts its body out of countenance, seeing that the arms in question are nearly four times as long as either the length or breadth of the carapace. In Lambrus intermedius, Miers (see Plate IV.), from the Corean Seas and Torres Strait, the disproportion between legs and trunk is less exaggerated. In the genus at large it is remarked that, apart from larval metamorphoses, so many variations

of form are undergone during progress to the adult condition, that, without a considerable series of specimens, young and old of the same species must often almost inevitably be considered as distinct.

Heterocrypta, Stimpson, 1871, contains but three species, and those of small size but singular appearance. One of these, Heterocrypta Maltzani, Miers, which has been taken at Goree Island, at the Azores, and off Senegambia, is also an ornament of the Mediterranean, having been taken by the Travailleur at a depth of about 250 fathoms off Toulon. The Mediterranean form was at first named Heterocrypta Marionis, after the distinguished French zoologist, but it has since been found to be the same species as Heterocrypta Maltzani.

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CHAPTER IX

TRIBE IV.-OXYSTOMATA

THE carapace is convex or depressed, with the anterolateral margins arcuate or orbiculate; or even subglobose; or more or less oblong, with subparallel or slightly convergent margins (Dorippidae). The epistome is very much reduced or rudimentary. The buccal frame is more or less triangular, nearly always produced and narrowed forwards with the margins anteriorly convergent. The afferent channels to the branchiæ open either behind the pterygostomian regions and in front of the chelipeds, or, more rarely, at the antero-lateral angles of the palate (Leucosiidae). The efferent channels open at the middle of the endostome which is produced forwards. There are six to nine pairs of branchiæ. The first antennæ fold longitudinally or obliquely. The third maxillipeds have the fifth joint articulated at the inner or the outer front angle or at the apex of the fourth, beneath which it is often concealed. The verges of the male are exserted either from the surface of the sternal plastron or more usually from the bases of the fifth pair of legs, which are either adapted for walking or for swimming, or are feeble and raised upon the dorsal surface of the carapace.

It is the narrowing anteriorly of the buccal frame or mouth-cavity' that gives the name of 'sharp-mouths' to this tribe, which is divided into four families, the Calappidæ, Matutidæ, Leucosiidæ, and Dorippida.

Family 1.-Calappida.

The afferent channels to the branchiæ open behind the pterygostomian regions and in front of the chelipeds.

The third maxillipeds have the fifth and following joints. not wholly concealed by the fourth joint. The verges of the male are exserted from the bases of the fifth pair of legs.

There are about ten genera included in this family.

Calappa, Fabricius, 1798, contains some fifteen species, which are not a little remarkable in appearance. This is partly due to the form of the carapace, much narrowed in front where the short-stalked eyes twinkle cunningly, but widened behind with shield-like expansions over the bases of the legs. More singular, however, is the development of the chelipeds, which have a very flat crested hand of great size, yet the whole limb withal so arranged that the pair can be concealed beneath the body to which in that position they might be said to supply an operculum or incomplete ventral carapace. Of Calappa granulata (Linn.) Stalio says that, when it is compelled by fear of some enemy or by the force of the waves to leave its crevice in the rock, it draws together its walking-legs under the expanded parts of the carapace, makes its chelipeds meet, and, being thus reduced to the shape of a ball, launches itself into the deep. Unfortunately for it, the scouring of the waves often throws it up on to the shore, where continuous rolling upon the pebbles puts an end to its existence. This is a waste of what would otherwise form an agreeable morsel. It may be eaten with a good conscience, since it is itself very voracious, and when in pursuit of prey not to be intimidated. Judging from the contents of the stomachs of various Crustacea, de Haan was able to decide that Calappa, Matuta, and Dorippe feed on other Brachyura, Leucosia on species of Palomon, Ranina on fishes and starfish. Calappa gallus (Herbst) is common to the Atlantic and the Pacific. The crested claws here carry to an almost comical extreme the resemblance to the head of a cock, which they exhibit more or less throughout this genus. Calappa depressa, Miers (see Plate II.), from the South Australian coast, is one of the smaller species and a recent contribution to science.

Paracyclois, Miers, 1886, is a genus in which the chelipeds and walking-legs agree with those in Calappa and

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Cryptosoma, and it is considered to connect Cryptosoma, Brullé, and Platymēra, Milne-Edwards, with Calappa through such forms as the above-mentioned Calappa gallus (Herbst), but Paracyclois is distinguished from the first two of these genera by the absence of any lateral spine on the margin of the carapace, and the broader basal joint of the second antennæ, and from Calappa by the absence of the clypeiform prolongations of the carapace, which are represented by a slight protuberance of the postero-lateral margins in Paracyclois, which protuberance bears several strong spines.' The type species of this curious genus, Paracyclois Milne-Edwardsii, Miers, was dredged north of the Admiralty Isles from a depth of 150 fathoms.

Cryptosoma cristatum, Brullé, was depicted in Webb and Berthelot's 'Hist. Nat. des Iles Canaries,' and the genus was instituted at page 16 of that work, for which Miers gives the dates 1836-1844. Milne-Edwards in 1837, while his own pages were passing through the press, refers to Brulle's genus and species as about to be published. In the same year, 1837, de Haan published a new genus and species, Cycloës granulosa, from Japan. In 1841 he states that Brullé's species is clearly the same as this, and in 1849 he repeats the remark as an example of wide distribution, the very same crab being found at the Canaries and in the waters of Japan. But he retains the name Cycloës, being evidently, and perhaps rightly, under the impression that it had priority over Cryptosoma.

Orithyia, Fabricius, 1798, is strongly distinguished from the other genera of this family by the natatorial character of the last three pairs of legs, which have an ovate terminal joint, as in the Portunidæ. The three preceding pairs of legs have also the terminal joints flattened, and the others more or less compressed, as is usual in species apt for swimming. There appears to be only one species, found in the Chinese Sea, and called bimaculatus by Herbst in 1790, and mammillaris by Fabricius in 1793. Herbst, whose specific name must prevail, says that without dispute this crab is one of the most beautiful and most rare.'