19U0.] FROM THE FALKLAND ISLANDS. 555 



lamellce of uropods, the inner of which is "rounded afc 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 perseon-segments fifth to seventh are scarcely shorter than 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 flatrellum of the second antennae 

 18-20 joints ; " the texture of the shell corneous, aa 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 aS'. 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 

 the longest, " the rest short, subequal, slightly tending backward 

 on the sides, and with the infero-posierior angle subacute," and 

 that the colour is " hght 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 distin- 

 guished 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 Tasmaninn and New 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 Guerm-Meneville some fifty years earlier, 

 bewailing the want of a monograph of the Sphaeromidae. 



Guerin-Meneville himself adds nothing to the knowledge 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 perseon] 

 and seven pairs of feet. These young ones were scarcely a milli- 

 metre long, their body was narrow, elongate, with segments well 

 marked and separated at the edges. The last pleon-segment v^ as 

 ordiform, 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 



[39] 



