(only species south of 35°S included)
For adult females (also for male A-1 of S. frons; unknown for S. sculpta)
1 Length of carapace shorter than 2.5 mm.................................................................... 2
- Length of carapace longer than 2.5 mm.................................................................... 4
2 Carapace with lateral ribs............................................................................... 3
- Carapace without lateral ribs....................................................................... S. wolffi
3 Second endopodial joint of antenna short, 7th limb without peg on opposite comb............................... S. pix
- Second endopodial joint of antenna long, 7th limb with peg on opposite comb................................ S. flexilis
4 Rostrum on valves of carapace with ventral horn............................................................. 5
- Rostrum on valves of carapace without ventral horn.......................................................... 6
5 Terminal comb of 7th limb has 8 teeth with long marginal spines, caudal furca with 15+15 claws.................. S. solox
- Terminal comb of 7th limb has 15–17 teeth with long marginal spines, caudal furca with 13+13 (14) claws........ S. arcuata
6 Terminal comb of 7th limb has bare teeth or pegs, base of Bellonci organ segmented................................. 7
- Terminal comb of 7th limb has alate teeth with short spines, base of Bellonci organ unsegmented....................... 8
7 Medial eye with 3 tubercles............................................................ S. tuberculata sp. nov.
- Medial eye bare.............................................................................. S. gallardoi
8 Carapace elongated, with thin ribs................................................................ S. edentata
- Carapace short, with thick ribs.................................................................. S. appelloefi