3IO DISCOVERY REPORTS 



second is about the same length only narrower ; the third and fourth sub-equal, longer 

 than the second. The flagellum consists of ten joints in the male and five in the female; 

 the first joint is short, the second more than twice as long as the first, the remaining 

 segments gradually decreasing in length and breadth to the penultimate one ; the terminal 

 segment is very small, bearing a sensory and two long simple setae. A single sensory 

 seta is present at the distal end of each flagellar joint. In the antenna the peduncular 

 joints are covered with microscopic imbricating scales, those of the fourth and fifth 

 joints larger than those of the other joints. The first peduncular joint is short, the second 

 twice as long as the first, both with fine hairs on their anterior margins ; the third is about 

 equal in length to the second, but not as broad ; the fourth joint is a little more than 

 twice the length of the third, its anterior margin bearing four groups of delicate setae on 

 slightly raised areas at points about equidistant one from the other ; the fifth joint is 

 about one and a half times the length of the fourth, with a similar arrangement of setae. 

 The flagellum is composed of seven joints, of which the first is the longest and broadest; 

 the terminal and penultimate joints are very small, together equal to about a third of the 

 length of the preceding one. Each joint is furnished with a short toothed spine at its 

 distal posterior angle and a few delicate setae at its anterior angle. 



Richardson's figures (1905, p. 321, fig. 354 b, c) of the maxillula and maxilla are quite 

 inaccurate : she shows only one distal lobe in the former and two in the latter appendage, 

 with none of the basal joints. Actually these appendages have the normal Isopod struc- 

 ture (see Figs, i a, c). 



The maxillula has eight curved setae on the truncate distal extremity of the outer 

 lobe ; the inner lobe is delicate, about two-thirds the length of the outer, curved out- 

 wards towards its distal end and with a single short seta. The maxilla has the usual two 

 setae on the distal ends of each of the two outer lobes, and seven or eight on the fixed 

 lobe. 



The lamella of the maxilliped (Fig. 11 rt) is not separated from the basipodite by a 

 suture, the union of the two extending beyond the articulation of the endopod, so that the 

 latter appears to spring from the centre of a plate-like structure. Such an arrangement 

 occurs also in S. exigiia, Nordenstam (Fig. 2 a), S. orbiculata, n.sp. and S. nototropis, 

 n.sp. The endopod is composed of three joints ; the second is long and narrow with its 

 distal angle somewhat produced, rounded, and bearing six setae; the terminal segment 

 has six setae on its rounded distal extremity. 



The cutting edges of the mandibles are simple, each with its distal extremity notched 

 to form three large rounded teeth. In the three-jointed palp the terminal joint is rather 

 short, with setae of the usual type on its posterior margin, and on that of the second 

 joint. 



The second, third and fourth thoracic appendages of the male are shown in Figs. 

 1 1 h-d. The propodus of the second is greatly expanded, with its inner margin armed 

 with a row of twenty-three broad, leaf-like, toothed processes (Fig. 1 1 b), alternating 

 with peculiar spines. The leaf-like processes are not unlike those found in a similar 

 position in S. elliptica, n.sp. The distal end of the carpus is crenulate, and bears two 



