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described both by him and by Alcock, is not found in the African specimen.

There are numerous groups of curved setæ on the frontal horns and in two lines to the middle of the carapace, thence diverging to the branchial regions. Many also are conspicuous at the bases of the lateral spines and about the walking legs, only leaving the dark ungues uncovered.

The length of the carapace is 100 mm., of which a straight line between the frontal horns measures 15 mm., the inner side of the horn being 18 mm. in length. The extreme breadth of the carapace is 85 mm., or 69 mm. without the projecting lateral spines.

Locality. Durban. The specimen from the Durban Museum was entrusted to me by the curator, J. F. Quekett, Esq., out of respect to whom the specific name is given.

Locality. Port Elizabeth. The specimen received from Mr. Fitz Simons under the circumstances above mentioned, has a carapace 130 mm. long, allowing 5 mm. for the broken tip of the least damaged frontal horn. The extreme breadth is 105 mm., or 90 mm. not including the lateral spines. The right cheliped measures 150 mm., of which 35 belong to the fifth joint, and 55 to the hand and fingers. Between these fingers when closed there is proximally a prolonged and rather conspicuous gap. In this specimen it is easy to see how strongly the orbits are excavated backwards. The eyestalks appear to be more strongly curved than in Mamaia squinado. They are rather bulbous at the base, but then narrow, with the visual area narrowly oval. The stout bifid spine at the centre of the carapace might in this example equally well be described as a closely contiguous pair of transversely placed spines. They are very prominent. In the other specimen unfortunately the bird's-eye view taken by the camera does not at all clearly show these sharp projections.

GEN. PLATYMAIA, Miers.

PLATYMAIA WYVILLE-THOMSONI, Miers.

1886. Platymaia wyville-thomsoni, Miers, Challenger Brachyura, Reports, vol. xvii., p. 13, pl. 2, fig. 1.

1902. Platymaia turbynei, Stebbing, S.A. Crust., pt. 2, p. 3, pl. 5. 1904. Platymaia wyville-thomsoni, Doflein, Valdivia Brachyura, p. 89, pls. 2, 20-23, &c.

It is desirable here to call attention, not only to Herr Doflein's identification of P. turbynei with the species named by Miers, but also to the very elaborate and valuable study of the species in the Brachyura of the Valdivia expedition.

FAMILY BLASTIDE.

1902. Blastidæ, Stebbing, S.A. Crust., pt. 2, p. 2.

1905. Blastidæ, Stebbing, S.A. Crust., pt. 3, pp. 22, 25.

For Alcock's equivalent sub-family Pisina see Journ. Asiat. Soc. Bengal, vol. lxiv., pt. 2, pp. 160, 165, 200, 1895, and Deep-sea Brachyura of the Investigator, p. 49, 1899.

GEN. HALIMUS, Latreille.

1829. Halimus, Latreille, Règne Animal, éd. 2, vol. iv., p. 60. 1831. Halimus, Latreille, Cours d'Entomologie, p. 362. 1834 (or earlier). Halimus, Guérin, Iconographie, Crust., pl. 9, fig. 2. 1834. Halimus, Milne-Edwards, Hist. Nat. Crust., vol. i., p. 340. 1895. Hyastenus, Alcock, Journ. Asiat. Soc. Bengal, vol. lxiv., pt. 2, pp. 200, 206.

1897. Halimus, M. J. Rathbun, Proc. Biol. Soc. Washington, vol. xi., p. 157.

1904. Hyastenus, Doflein, Valdivia Brachyura, p. 85.

Miss Rathbun has explained that when Latreille defined this genus he did not name the species belonging to it. Guérin, who is quoted by Milne-Edwards in 1834, assigned to the genus the single species Halimus aries, Latreille, which must therefore be regarded as the type, since there was at the time no competitor in the field. Milne-Edwards assigned to the genus the additional species H. auritus (Latreille). Unluckily the first species was included in White's genus Hyastenus, 1847, thus constituting Hyastenus a synonym of Halimus.

The points on which Latreille relied for defining his genus were that the ocular peduncles, though short, are always exposed, and that the second antennæ have the third joint of the peduncle at least as long as the preceding joint, and carrying a long setaceous flagellum. He considered the genus to be near Micippe, Leach, and discusses it between Leach's genera Camposcia and Hyas.

For the modern definition see the references to Hyastenus, Alcock.

HALIMUS DIACANTHUS (de Haan).

1839. Pisa (Naxia) diacantha, de Haan, Crust. Japon., decas quarta, p. 96, pl. 24, fig. 1 (1838), and pl. G.

1895. Hyastenus diacanthus, Alcock, Journ. Asiat. Soc. Bengal, vol. lxiv., pt. 2, pp. 208, 210.

1902. Halimus diacanthus, M. J. Rathbun, U.S. Nat. Mus., vol. xxvi., p. 29.

1903. Hyastenus diacanthus, Nobili, Boll. Mus. Zool. Torino, vol. xviii., N. 455, p. 27.

The synonymy of the species down to 1895 is supplied in the reference to Alcock, the transference to Hyastenus commencing with A. Milne-Edwards in 1872. The distribution of the uncinate setæ is discussed by C. W. S. Aurivillius in his treatise on the masking habits of the Oxyrrhyncha, p. 51, pl. 2, fig. 5, 1889. Among the numerous Indian species Alcock distinguishes the present one as belonging to a group in which the carapace when denuded is smooth and polished, with a few large spines; in common with H. spinosus, A. Milne-Edwards, it has the "carapace triangular, with a large epibranchial spine and at least one large subhepatic tubercle on either side," and is distinguished from the species mentioned by having a single acuminate tubercle in the middle line on the gastric region, and none on the intestinal, whereas H. spinosus has "a large intestinal and two large gastric spines in the middle line."

The specimen from Durban agrees with the description of H. spinosus, in that the gastric hump has two spines in the middle line and that there is a spine on the intestinal hump, but they are of insignificant size, the hinder one on the gastric region being hidden in the fur and scarcely even palpable. They do not seem characters sufficient for bestowing specific rank. The carapace, including the straight divergent horns, is 80 mm. long, and, including the lateral epibranchial spines, its breadth is 48 mm. The length of a horn on the free inner margin is 25 mm. The specimen is a female, and the slender chelipeds are considerably shorter than the next peræopods.

CYCLOMETOPA.

FAMILY XANTHIDE.

1898. Xanthida (part), Alcock, Journ. Asiat. Soc. Bengal, vol. lxvii., pt. 2, pp. 67, 69.

1898. Xanthine (sub-fam.), Alcock, loc. cit., p. 77.

Alcock defines his family Xanthida as one "in which the fold of the antennules is transverse or obliquely transverse, and the anterior boundary of the buccal cavern is raised and sharply defined, so that the external maxillipeds commonly shut close against it unless they

fall short of it." He divides it into three sub-families-Xanthinæ, Actæinæ, and Chlorodina-which I prefer to treat as families, accepting for the first the name Xanthidæ in a restricted sense. For this Alcock's definition is: "Carapace usually much broader than long, usually transversely oval, sometimes transversely hexagonal. The front is contained from 3 to 5 times in the greatest breadth of the carapace."

It is subdivided into six so-called alliances, the fourth of which, called Xanthoida, contains among others the typical genus Xantho, Leach, followed by Leptodius, which is presently reduced to a sub-g -genus of Xantho.

The remarks made by Miers in his Alert and Challenger reports on the species which have been referred to Leptodius, A. Milne-Edwards, 1863, will incline many to agree with Dr. Ortmann, when he says (Zool. Jahrb., vol. vii., p. 443, 1893): "I am unable sharply to distinguish the three genera Xantho, Xanthodes, and Leptodius." The last is chiefly distinguished by the spoon-shaped tips to the chelipeds. But Ortmann observes that a typical Xantho (rivulosus) has them, and Alcock remarks that in Leptodius crassimanus the spooning of the figures is indistinct. The latter species is, perhaps for that reason, referred to Xantho by Miss Rathbun

in 1906.

GEN. XANTHO, Leach.

1814. Xantho, Leach, Edinburgh Encycl., vol. vii., p. 430.

1898. Xantho, Alcock, Journ. Asiat. Soc. Bengal, vol. lxvii., pt. 2, p. 112 (including Leptodius).

XANTHO HYDROPHILUS (Herbst).

1790. Cancer hydrophilus, Herbst, Naturg. Krabben u. Krebse, vol. i., pt. 8, p. 266, pl. 21, fig. 124.

1801. Cancer Eudora, Herbst, Naturg. Krabben u. Krebse, vol. iii., pt. 2, p. 10, pl. 51, fig. 1.

1826? Cancer inæqualis, Audouin, Savigny's Crust. Égypte, pl. 5, fig. 7.

1834. Chlorodius exaratus, Milne-Edwards, Hist. Nat. Crust., vol. i., p. 402.

1834. [?] Chlorodius eudorus, Milne-Edwards, loc. cit., p. 402. 1835. Cancer (Xantho) affinis, de Haan, Crust. Japon., decas secunda, p. 48, pl. 13, fig. 8 (f. 6 in text).

1843. Xantho affinis, Krauss, Südafrik. Crust., p. 30.

1868. Leptodius exaratus, A. Milne-Edwards, Nouv. Archiv. du Mus., vol. iv., p. 71.

1884. Leptodius exaratus, Miers, Crust. H.M.S. Alert, p. 214. 1886. Leptodius exaratus, Miers, Challenger Brachyura, Reports, vol. xvii., p. 137.

1893. Xantho exaratus, Ortmann, Zool. Jahrb., vol. vii., p. 445. 1898. Xantho (Leptodius) exaratus, Alcock, Journ. Asiat. Soc. Bengal, vol. lxvii., pt. 2, p. 118.

1906. Leptodius exaratus, M. J. Rathbun, U.S. Fish. Comm. for 1903, pt. 3, p. 847.

1906. Leptodius exaratus, Nobili, Bull. Sci. France-Belgique, vol. xl., p. 121.

1907. Chlorodius exaratus, Stimpson, North Pacific Expl. Exp. 1853-56, Smithsonian Misc. Coll., vol. xlix., p. 52, pl. 6, figs. 3-4, 6-9 (posthumous publication).

A full synonymy of this species from Audouin down to 1898 is supplied under the reference to Alcock, apart from some of the names which Miers gives in his Challenger report as possibly only varieties, and not including Xantho rivulosus (Risso), MilneEdwards, of which Bell (Brit. Stalk-eyed Crust., p. 55, 1853) says, "There can be no doubt that this is the Cancer hydrophilus of Herbst."

The Durban specimen corresponds with Alcock's description, having "front not very prominent, but projecting beyond the inner angle of the orbit, from which it is separated by a notch; bilaminar, the lobes cut square, but with a slightly concave margin." The fingers of the chelipeds are black; those of the walking legs are granular, furred along both edges as far as the claw.

The specimen, a male, has the carapace 22 mm. long by 30 mm. broad.

A long discussion of this species, with nine named varieties, by the distinguished carcinologist, William Stimpson, appears in the work which, as already mentioned, has just been published by the Smithsonian Institution thirty-five years after its author's death.

FAMILY PORTUNIDÆ.

1899. Portunidæ, Alcock, Journ. Asiat. Soc. Bengal, vol. lxviii., pt. 2, pp. 4, 5.

Alcock divides the family into four sub-families, of which the first, called Lupinæ, is thus defined: "The chelipeds are longer, usually

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