. The Cambridge natural history. Zoology. i68 CRUSTACEA EUCARIDAâDECAPODA It is not much reduced in size, and the pleopods of the sixth pair are fairly well developed, but it is usually carried flexed towards the thorax, and is never a powerful locomotory organ as in the Macrura. The antennal scale, if present at all, is a mere spine, not the large leaf-like structure of the Macrura ; and there is never a partition between the two first antennae as in the Brachyura. The last or last two pairs of pereiopods are reduced, and are turned on to the dorsal surface or carried inside the branchial cha
. The Cambridge natural history. Zoology. i68 CRUSTACEA EUCARIDAâDECAPODA It is not much reduced in size, and the pleopods of the sixth pair are fairly well developed, but it is usually carried flexed towards the thorax, and is never a powerful locomotory organ as in the Macrura. The antennal scale, if present at all, is a mere spine, not the large leaf-like structure of the Macrura ; and there is never a partition between the two first antennae as in the Brachyura. The last or last two pairs of pereiopods are reduced, and are turned on to the dorsal surface or carried inside the branchial chamber; but this curious character is met with again in certain Brachyura (Dromiacea and Oxystomata). Tribe 1. Galatheidea/ These are symmetrical crabs with a long carapace; the abdomen, which is as broad as the carapace, is always carried flexed under the thorax, and the sixth pair of pleopods are expanded to form with the telson a fan- like tail. The most anterior pereiopods are always much elongated and chelate ; while the last pair are much re- duced, and either turned up on to the dorsal surface, or else carried in the branchial chamber. The exact mean- ing of this last characteristic in these forms is doubtful; some of the species are said to carry shells temporarily upon their backs, a proceed- ing probably assisted by the last pair of thoracic limbs. Fig. m.âTioisai view of Munidopsis hamata, while in others their limbs xi (From an original figure prepared J ^g ^^^^ f^^, cleaning lor Professor weldon.) â ' o out the brancliial chamber. Most of the Galatheidea, for instance, the common Porcellana and ^ Milne Edwards and Bouvier, Ann. Sci. Nat. (7), xvi., 1894, p. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Harmer, S. F. (Sidney Frederic), Sir, 1862- ed; Shipley, A. E. (Arthur Everett), Sir,
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
