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Show 1900.] FROM THE FALKLAND ISLANDS. 555 lamellae of uropods, the inner of which is " rounded at extremity, but subacute." The length of specimens was four to five lines, the colours brown to brownish black, with some irregular whitish spots. Of the " large " " Spheroma lanceolata " from Fuegia he figures and describes the mouth-organs. Further, he states that the peraeon-segments fifth to seventh are scarcely shorter thau the three preceding, that the caudal shield is evenly convex, its sides arcuate, its apex rather narrowly rounded, reached by the inner lamella of the uropods, which is equal to the outer lamella, and like it lanceolate, obtuse; the flagellum of the second antennae 18-20 joints: " the texture of the shell corneous, as usual." Cunningham asks, as he well might, "Is this species truly distinct from S. gigas Leach ? " Miers suggests that the differences may be only sexual. After describing specimens referred to the Aucklands, the Falklands, and Fuegia, he says that S. lanceolata, from the two latter localities, " differs only in the rami of the caudal appendages, which are narrower-lanceolate and acute at the extremity, and in the absence of the lateral marginal groove on the thoracic segments." In S. gigas he notes " inferior lateral margins of all the segments grooved," and " rami of the caudal appendages narrow-oval, rounded at the extremity." To these characters he adds that the front margin of the transversely oblong head has a very small lobe between the enlarged bases of the first antennae, that the first segment of the peraeon is rather tbe longest, " the rest short, subequal, slightly tending backward on the sides, and with the infero-posterior angle subacute," and that the colour is " light brown, margins of segments yellowish ;" " length nearly 1 in." Haswell only repeats the description given by Miers; and Studer thinks the lanceolatum of Fuegia is distinguished from the S. gigas of Kerguelen by its slenderer body and the shape of the caudal shield. Beddard notices S. gigas as a species without prominent sexual dimorphism. Thomson records under this name a small Tasmanian and N e w Zealand form, which, he says, "differs in a few details from a large form" found in the Auckland Islands. What the details are he has at present left untold, though, like Guerin-Meneville some fifty years earlier, bewailing the want of a monograph of the Sphaeromidae. Guerin-Meneville himself adds nothing to the kuowledge then available of the adult S. gigas, but makes the following statements in regard to the young. He has found, he says, " under the ventral plates (feuillets inferieurs) of a female a great number of eggs and some young individuals just hatched and still attached to the mother by a filament which issued from their anus, and he found that these individuals had seven segments [of the peraeon] and seven pairs of feet. These young ones were scarcely a millimetre long, their body was narrow, elongate, with segments well marked and separated at the edges. The last pleon-segment was cordiform, rounded at the sides, pointed behind, and the lamellae of the uropods were inserted far back on this tail-piece (fort en arricre de cette queue) and extended a little beyond it." He |