4. POLYDECTINE.-Antennæ internæ transversa. Antennæ ex ternæ basi solutæ, liberæ.-An Pilumnis propinquior? G. POLYDECTUS, Edw.*-Orbita dentibus tribus infra instructa. Manus elongata, digitis prælongis, attenuatis, uncinatis, cum dentibus tenuiter spinuliformibus sæpe armatis. FAM. II. ERIPHIDE. Pedibus maxillipedeque Imo Cancridis affinis. Palatum colliculo usque ad marginem anticum producto utrinque divisum. Carapax sæpius angustus, interdum latus, latitudine ante-medianâ sæpissimè majore, oculis remotis. 1. THRINE.-Carapax transversus, lateribus valde dilatatus et rotundatus. Antennæ internæ fere longitudinales. G. 1. ETHRA, Leach. 2. OZINE.-Carapax plus minusve transversus. Digiti acuminati. Antennæ internæ transversæ. Orbita hiatu interno basi antennæ occupato instructa. Abdomen maris 7-articulatum. 1. Articulus antennæ externæ Imus frontem bene attingens. G. 4. PILUMNUS, Leach.-Carapax angustus, parce transversus, G. 5. PILUMNOIDES, Edw. et Lucas.§-Carapax angustus, parce transversus, valde convexus, margine antero-laterali longiore, bene arcuato, super carapacem postice incurvato. *This genus is very peculiar in the hand: both fingers are long styliform and very slender, with incurved apices, and hardly touching except at tips, and when dentate the teeth are delicate spines on the inner margin; moreover, the part of the hand anterior to the fingers is quite short. A species collected by the writer is closely like the P. cupulifer in most of its characters. The form of the hand is very unlike anything among other Cancroidea; and Halimede which has been supposed to be near Polydectus, has (like Medaus) the ordinary form, like that in Xantho. The genus Iphiculus of White (Crust. Voy. Samarang, 57, pl. 13, f. 5), has the general characters of our Polydectus-the same villous coat, similar fingers, even to the spiniform dentation of the fingers, and other resemblances; and we suspect although a broader species, that his I. spongiosus is a true Polydectus. The specimen of the Polydectus, from which a description with a colored drawing was taken by me while it was living, is not now found in our collections, and I have not therefore been able to ascertain the character of the prælabial plate and thus assure myself whether the species are related to the Eriphidae or not. It is very possible that the true place is after Ozinæ. Faun. Japon. 19. Near Pseudocarcinus, from which it differs in the ridge on the prælabial plate, as well as in its flatter form. Crust. D'Orb. S. Am., 21. G. 6. MELIA, Latr.-Carapax subquadratus, fere planus, fronte lato, oculis versus angulos insitis. Pedes toti graciles. Basis antennæ externæ cylindricus. An genus sequens hîc pertinet? ACANTHODES, De Haan.*-Carapax angustus, Pilumno formâ affinis, spinis grandibus anticè armatus. Pedes spinosi.-Species Acanthodes armatus Haanii magnitudine portentosus. 3. ACTUMNINÆ.-Orbitâ Ozinis similis. Digiti instar cochlearis excavati. G. ACTUMNUS, Dana.t-Carapax paulo transversus, valde convexus, antice lateraliterque curvatim declivis. Articulus antennæ externæ 1mus processum frontis attingens tantum. 4. ERIPHINE.-Orbita infra bene clausa, hiatu interno carens, articulo antennæ e orbitâ omnino excluso. Carapax sive paulo transver sus sive subquadratus. G. 1. RUPPELLIA, Edw.-Carapax latior. Antennæ pars mobilis externæ orbitâ paululum remota. Articulus maxillipedis externi 3tius paulo transversus. G. 2. ERIPHIA, Latr.-Carapax angustus, convexus, fronte sæpius G. 4. TRAPEZIA, Latr.-Carapax subquadratus, planus, glaber, G. 5. TETRALIA, Dana.S-Carapax aspectu Trapezia affinis. Frons FAM. III. PORTUNIDE. Pedes postici natatorii, tarso laminato. Ramus maxillipedis 1mi internus lobo interno instructus. Palatum colliculo utrinque sæpissime divisum. Corpus sive latum sive angustum, oculis sat brevibus. *Faun. Japon. 20. + Very near Actaea, but the prælabial plate or palate is strongly divided by a ridge either side. Besides, the form is much narrower and more convex than in the Actææ, being subglobose above. Voy. of the Bonite; also, "Voy. au Pole Sud," under D'Urville, in the Astrolabe and Zélée, plate 6, figs. 3-7, by Hombron and Jacquinot. § This Journal, [2] xi, 223. by 1. LUPINE.-Sutura sterni mediana segmenta tria intersecans. Palati colliculi prominentes. 1. Pars antennæ externæ mobilis hiatu orbitæ non occlusa, orbitâ jacendo aptata. G. 1. SCYLLA, De Haan.*-Valde latus et crassus, marginibus anterioribus simul sumtis bene arcuatus, antero-laterali longiore quam postero-lateralis. Pedes antici breviores, crassissimi, manu valde tumidâ, non angulatâ vel prismaticâ. G. 2. LUPA, Leach.t-Valde latus, marginibus anterioribus totis simul sumtis bene arcuatus. Manus elongatè trigona aut prismatica, costata. G. 3. AMPHITRITE, De Haan,‡ Dana.-Angustior. Margines frontalis antero-lateralisque angulo convenientes, antero-laterali raro breviore quam postero-lateralis. Manus elongata, prismatica. Basis antennæ externæ crassus, hiatu orbitæ parce angustior. G. 4. CARUPA, Dana.-Transversus. Margines frontalis anterolateralisque angulo convenientes, fronte recto, emarginato. Basis antennæ externæ subcylindricus, hiatu orbitæ multo angustior. 2. Pars antennæ externæ mobilis hiatu orbitæ omnino per basis processum occlusa, orbitâ plus minusve remota. G. 5. THALAMITA, Latr.-Latus. Frons dimidio latitudinis carapacis longior; margo antero-lateralis longitudinalis. Articulus antennæ externæ Imus prælongus, 2dus orbitâ remotissimus. Pedes antici longi, manu elongatâ. G. 6. CHARYBDIS, De Haan, Dana.§-Angustior. Frons dimidio latitudinis carapacis brevior; margo antero-lateralis obliquus. Articulus antennæ externæ Imus paulo oblongus, 2dus orbitâ paulo remotus. Pedes antici longi, manu elongatâ. G. 7. LISSOCARCINUS, White.-Suborbiculatus, lævis, subporcellanus. Articulus antennæ externæ Imus brevis, fere longitudinalis, articulo sequente orbitâ parce remoto. Pedes nudi; antici breves, brachio ultra carapacem vix saliente, manu perbrevi. 2. ARENEINE.-Sutura sterni mediana segmenta tria intersecans. Palatum colliculo utrinque non divisum. Ramus maxillipedis 1mi internus ad apicem late transversim triangulatus lineamque medianam fere attingens. * Faun. Japon. 11. Neptunus, Pontus and Achelous of De Haan, (Faun. Japon., 8, 9,) the distinctions between which genera appear not to be sustained. Faun. Japon. 8. Includes, as here adopted, the Lupa of De Haan, which division he restricts to the Lupa forceps (Edw. Crust. i, 456). The Lupocyclus of Adams and White, (Crust. Voy. Samarang, 47, pl. 12, f. 4,) appears to be identical with Amphitrite. Fauna Japon. 10. Includes both Charybdis and Oceanus of De Haan, which divisions shade into one another by imperceptible gradations, and are not distinguished by any important characters. Corresponds to the "Thalamites Hexagonales" of Edwards. Crust. Voy. Samarang, 45. We have taken the generic characters from a species collected by us, in connection with the description by White. SECOND SERIES, Vol. XI, No. 31.-July, 1851. 17 G. ARENEUS, Dana.-Lupa affinis. Carapax valde latus, antice arcuatus. Pars antennæ externæ mobilis hiatu orbitæ insita. Manus prismatica.* 3. PORTUNINÆ.-Sutura sterni mediana segmenta duo intersecans. Colliculi palati sæpius obsoleti. G. PORTUNUS, Fabr.-Angustus, margine antero-laterali breviore quam postero-lateralis. FAM. IV. PLATYONYCHIDE. Pedes postici natatorii, tarso laminato. Ramus maxillipedis Imi internus lobo interno non instructus. Palatum colliculo utrinque non divi. sum. Corpus angustum. G. 1. CARCINUS, Leach.t-Pedes postici male natatorii, tarso angustè lanceolato. Carapax parce transversus. G. 2. PORTUMNUS, Leach.-Pedes 5ti natatorii tantum, tarso lanceolato, acuto. Carapax non latior quam longior. G. 3. PLATYONYCHUS, Latr.‡-Pedes 5ti natatorii tantum, tarso lato, elliptico. Carapax latior quam longior. G. 4. POLYBIUS, Leach.-Pedes 2di, 3tii, 4ti, 5ti toti natatorii, tarsis late lanceolatis. Pedes postici natatorii, tarso laminato. Ramus maxillipedis Imi internus lobo interno instructus. Corpus latum, antice valde transver sum, orbitis oculisque longissimis. G. PODOPHTHALMUS, Lamarck. LEGIO II. TELPHUSINEA, VEL CANCROIDEA GRAPSIDICA. FAM. I. TELPHUSIDE. Carapax subquadratus aut orbiculato-quadratus. Palatum colliculo utrinque sæpius divisum. [Species Eriphiis paulo affines.] G. 1. TELPHUSA, Latr.-Articulus maxillipedis externi 3tius subquadratus, 2dus oblongus. Carapax subquadratus. G. 2. TRICHODACTYLUS, Latr.-Articulus maxillipedis externi 3tius subtriangulatus, 2dus oblongus. * This genus is instituted for the Lupa cribraria, which differs from the other Lupas in the characters stated. This species occurs in the shallow waters off a sand beach. Xaiva of M'Leay (Smith's Illust. Zool. S. Africa) is described as near Carcinus. The narrow form is the same; the antero-lateral margin 1-dentate and shorter than the postero-lateral; the tarsus of the 5th pair of legs wider than in Carcinus; the 3d joint of the outer maxillipeds subquadrate and carinate at base, with the inner margin emarginated for the next joint just above its middle, a form which occurs in Platyonychus. Anisopus of De Haan, Faun, Japon. G. 3. VALDIVIA, White.*-Articulus maxillipedis externi 2dus brevior quam latior, 3tius longior quam latior. Palatum colli G. 4. POTAMIA, Latr.-Articulus maxillipedis externi 3tius apice subtriangulatus anguloque apicali 4tum gerens. culo utrinque bene partitum. An hîc pertinet genus Galene Haanii ?† LEGIO III. CYCLINEA, VEL CANCROIDEA CORYSTIDICA. Pedibus maxillipedeque Imo CANCRIDIS affinis. Palatum colliculo utrinque non divisum. Antennæ externæ obsoleta. Carapax angustus, suborbiculatus. Branchiæ numero septem. G. 1. ACANTHOCYCLUS, Lucas.‡-Carapax orbiculatus. Pedes longitudine mediocres, tarso uncinato. G. 2. CORYSTOIDES, Lucas.§-Carapax oblongus, ellipticus. Pedes longiores, tarso styliformi, longo. Antennæ internæ fossis. carentes. 2. Additional note to the Remarks on the Classification of the Maioidea; by JAMES D. DANA.||-The following genus by Kröyer¶ should be added to the synopsis given in the last number of this Journal. It appears to belong to the subfamily Inachinæ, and is classed near Inachus by its author. The species on which the genus is founded is the Cancer phalangium of Fabricius, Faun. Groenl. n. 214, and his Cancer Opilio in Det danske Vid. Selsk. Skr. nye Saml. iii, 180. It is from Greenland. Kröyer gives the following generic characters: G. CHIONOCETES.-Cephalothorax depressus, subtriangularis, eadem fere longitudine ac latitudine, antice truncatus, fronte lata rostroque horizontali, bifido, brevissimo. Pedes 2di paris duplicem cephalothoracis longitudinem superantes, triplicem vero non attingentes; pedes Imi paris 2dis tertiisque breviores, cephalothorace vero longiores (interdum duplo); chelis acuminatis, falcatis; pedes 2di, 3lii, 4tique paris compressi, 5ti paris subcylindrici. 3tius pedum maxillarium externorum articulus fere quadratus eadem pæne longitudine ac latitudine; 4tus articulus angulo interno tertii adnexus; oculi crassi, in orbitam retractiles; pars antennarum externarum terminalis mobilis brevissima. Abdomen sex constat articulis.-The name Chionocetes is from xv, nix, and oixins, incola. * Ann. and Mag. Nat. Hist., xx, (1847,) 206. See page 127, where it is placed with the Ozine. The branchial cavity is very large, as in Potamia, and contains outside of the branchia a large open space. The shell of a specimen from the Sandwich Ids. closely like the G. natalensis of Krauss, has the appearance of a fresh-water or land species, the texture being less calcareous than in most marine species. The specimen was not collected by the writer, and its exact habitat is not known. Krauss's species occurred under stones on the shores at the mouth of a river in South Africa. Crust. D'Orbign. S. Am. 29, pl. 15, ¶ Tidskrift, ii, 249. |