161 



24. Pereopods VI: 6th segment equal to or slightly shorter than 5th — 



25. 



— Pereopods VI: 6th segment longer than 5th 27. 



25. Pereopods and uropods very long and thin. Pereopods VI: 4th seg- 

 ment roughly 1.5 times longer than 5th 19. S. stenopusStehb. 



— Pereopods and uropods not abnormally long. Pereopods VI: 4th seg- 

 ment equal to or shorter than 5th 26. 



26. Pereopods V: 2nd segment denticulate along anterior margin. Pere- 

 opods VII: 6th segment considerably longer than 5th 



5. S. langhansi Wagl. 



— Pereopods V: 2nd segment smooth along anterior margin, only at 

 base of distal process may have one-two denticles. Pereopods VII: 

 6th segment shorter than 5th 20. S. tullbergi (Bov.) 



27. Pereopods V: 2nd segment armed with large denticles on anterior 

 and posterior margins 15. 5. antarctica Wagl. 



— Pereopods V: anterior margin of 2nd segment smooth or with 1-2 

 (rarely 3^) more or less conspicuous denticles (seen only during 

 examination in profile) at base of distal process. Posterior margin 

 denticulate 28. 



28. Pereopods V: anterior margin of 2nd segment only at base of distal 

 process with solitary denticles; posterior margin armed with large 

 denticles 29. 



— Pereopods V: anterior margin of 2nd segment smooth; posterior mar- 

 gin denticulate 31. 



29. Pereopods V: 5th segment twice or more longer than 6th. Pere- 

 opods V and VI very long and thin 14. S. rattrayi Stebb. 



— Pereopods V: 5th segment only slightly longer than or equal to 6th 

 30. 



30. Uropods narrow; exopodite of uropods I very long, roughly 2/3 

 length of basipodite and twice longer than exopodite of uropods II. 



Long seta above claw of pereopods V and VI 



23. 5, setigera Wagl. 



— Uropods broad, exopodites of uropods I and II small, spinelike. Setae 

 above claws of pereopods V and VI absent 22. 5. nana Wagl. 



31. Pereopods V: 2nd segment coarsely denticulate on posterior margin. 

 Pereopods VI: 6th segment slightly longer than 5th. Uropods broad. 

 Length of outer lobes of maxillipeds at least two times their width . . 

 21.5. similis Stebb. 



— Pereopods V: 2nd segment finely denticulate on posterior margin. 

 Pereopods VI: 6th segment almost 1 .5 times longer than 5th. Uropods 

 narrow. Length of outer lobes of maxillipeds twice their width — 

 26. S. latifrons Wagl. 



