I. '08. 31 



to that of S. robustus, but the appendix is provided with a 

 single very stout apical spine. In the female the lower 

 flagellum is simple and considerably shorter than the ulti- 

 mate peduncular segment. The upper flagella are almost as 

 long as the abdomen and telson ; proximally they are swollen 

 and setose. 



The antennal scale (fig. 13) is more than half the length of 

 the carapace ; it is rather less than four times as long as broad 

 and is much narrowed distally. The outer margin is convex, 

 terminating anteriorly in a very small spine which scarcely 

 surpasses the lamellar portion. The very long antennal 

 flagella show the characteristic bend or kink noticed in the 

 last species. 



The mandibles, maxillae, and first two pairs of maxillipedes 

 do not differ much from those of S. robustus. The ultimate 

 joint of the mandibular palp is a trifle longer in proportion to 

 the penultimate ; the exopod of the second maxilla reaches a 

 little further forward, while the endopod of the first maxilli- 

 pede is much longer. The third inaxillipedes reach beyond the 

 distal segments of the antennular peduncle by more than the 

 ultimate segment ; they are thus rather longer proportionally 

 than in S. robustus, but, as in that species, the proximal joints 

 are not obviously thicker or coarser than those of the third 

 pereiopod, and the tw^o terminal segments bear setae on both 

 mai'gins. The ultimate segment (fig. 17) is sub-divided into 

 six joints, the proximal of which is equal in length to the 

 three distal. 



The fi^rsi pair of pereiopods reaches almost to the middle of 

 the ultimate segment of the antennular peduncle, the second 

 reaches beyond it by about one-third of the propodus, while 

 the third, which is considerably longer than the third maxilli- 

 pedes, surpasses it by about half the length of the propodus. 

 The propodi of all three pairs are multiarticulate. The fourth 

 ?ind fifth pairs of pereiopods are considerably shorter, and their 

 joints, although laminar, are much less broad than is the case 

 in the preceding species. The proportional lengths of the 

 segments of the fourth pair are much the same as in S. robus- 

 tus, but in the fifth the merus is longer than either the ischium 

 or the carpus. The fourth pair is slightly shorter than the 

 length of the carapace ; the fifth is only half as long. 



The branchial formula is the same as that of S. robustus, 

 but the pair of pleurobranchiae over the base of the fourth 

 pereiopod are much smaller, in comparison with those of the 

 preceding somite, than is the case in that species.^ 



In the male tlie petasma (fig. 14) is identical in general plan 

 with that of S. robustus, but differs from it in several minor 

 details. The chief of these are the sharp point w^ith which it 

 is provided on the inferior margin , near the line of connection 

 of the right and left halves, and the series of processes, tipped 



1 For a fuller description of these branchiae and an account of their 

 difference from those of the allied 8. similis, see Hansen, 1903 (sub <S. 

 similis). 



