712 T. R. R. STEERING. 



but without forming an elongate lobe; the sixth is fully as long as the fifth, but much 

 narrower; it is broader and longer than the seventh, but forms no distal lobe. The armature 

 is feeble, except on the apex of the plate of the second joint. 



The anterior limbs of the peraeon are rather robust, the first pair distinguished from 

 the rest by the fifth joint underriding the sixth, its triangular form allowing the fourth and 

 sixth joints to meet on their outer margin. In the more elongated limbs of the last three 

 pairs the fifth joint has its share in the lengthening. In all the limbs the finger has a 

 little hooked spine in advance of the small hooked unguis. The male appendages of the 

 last peraeon-segment are elongate, close together at the base, with their stiliform apices a 

 little divergent. 



The male appendage of the second pleopod appears to be of unusual breadth at the 

 base, then tapering to a narrow apex at some distance beyond the plate that carries it. In 

 Sphaeroma rugicmida this appendage is very long and has a somewhat widened rounded apex. 



In the uropods the movable outer ramus is serrate almost all along the outer margin 

 as well as on the rounded apex, in the ramus coalesced with the peduncle the serration 

 reaches up the outer margin barely halfway. Length 3 mm., by a breadth of 1-5 mm. 



Locality. Lagoon, Minikoi, along with a specimen of Ligia. 



Heller in the Crustacea of the Novara Expedition, pi. 12, figures three species each with a 

 foramen in the telsonic segment, which he names respectively Sphaeroma perforata, Milne-Edwards, 

 S. stimpsoni, n. sp., and iS. scabricida, n. sp. None of them can be confused with the present 

 species. The first is easily distinguished by the long median tooth of the last peraeon- 

 segment. But it claims attention here as having the same sexual difference in the telsonic 

 segment as our species exhibits. Heller is certainly wrong in attributing the circular 

 aperture to the female and the simply notched telson to the male. He also says that the 

 postero-median tooth of the peraeon is shorter in the male than in the female, as to which 

 the reverse may be taken for gi-anted. But his text is plainly contradicted by the explana- 

 tion of the plate above cited. 



Gen. Gymodoce, Leach. 



Cymodoce, 1814, Leach, Edinh. Encycl, Vol. vii. p. 43.3; 1902, Stebbing, South African 

 Crustacea, Part 2, p. 73. 



The difficulties connected with the definition of this and various other genera of the 

 Sphaeromidae are discussed by Mr Beddard in his Challenger Isopoda, Reports, Vol. 17, p. 145. 

 Until a monograph of the family is carried out by some patient and skilful hand these 

 difficulties are likely to remain. The incapacity of the animal to become completely globular, 

 the resistance to complete folding of one plate over the other in the uropods, and the presence 

 of a lobe in the excavated apex of the telson, are superficial characters which do not offer 

 very firm ground for generic distinction. The maxillipeds do not differ from those found in 

 Exosphaeroma gigas, and in most of the species which I have assigned to that genus. 



10. Cymodoce bicarinata, n. sp. PI. LII B. 



The head broad, the first segment of the peraeon the longest, the sides of the body 

 very hirsute, and the hind margins of the segments hairy, the sixth and seventh also 

 tuberculose. In the pleon a small first segment is covered by the peraeon, the composite 



