o 



9 



3. Eyes large. Antennal squama narrow, at least about five times 



as long as broad ^. Thompsonii M.-Edvv. 



3. Eyes small. Antennal squama moderately broad, about three times 



as long as broad 5. gracilis Dana. 



4. Telson with two pairs of long terminal spines, the outer pair 

 somewhat longer than the inner. (Exopod of uropods with 6 to 



9 marginal spines) 5". quadrispinosa n.sp. 



4. Telson with a single pair of very long terminal spines close at 

 the three small median spines and much longer than the pair at 



their outer side 5. 



5. At most nearly one-third of the margin of the proximal joint of 

 the exopod of the uropods furnished with spines. Spines along 

 the distal third or at least almost the distal fourth of the lateral 

 margins of the telson increasing regularly in length backwards. 

 The rami of fourth (and third) pair of male pleopods subsimilar 



in length, with all their distal setae normal as in the other pairs 6. 



5. More than half of the margin of the proximal joint of the exopod 

 of the uropods furnished with spines. Spines along the distal third 

 of the lateral margins of the telson very irregular, as smaller or 

 small spines are intermingled between considerably larger spines. 

 The endopod or both rami of fourth (in one species besides the 

 endopod of third) pair of male pleopods with the most distal setae 



peculiarly developed and the rami in question a little elongated 8. 



6. Third pair of thoracic legs about two-thirds as long again as first 

 pair. Female with two nodiform conspicuous protuberances in the 



median line of the carapace S. nodosa n. sp. 



6. Third pair of thoracic legs not elongated, less than one-third as 

 long again as first pair. No protuberances in the median line of 



the carapace 7. 



7. Antennal squama with the terminal lobe unusually long, at least 



two-thirds as long as broad S. vulgaris n. sp. 



7. Antennal squama with the terminal lobe always less than two- 

 thirds and frequently only half as long as broad 5. affinis n. sp. 



8. The endopod of the uropods reaches about or quite the end of 

 the exopod. Abdomen with black lateral spots. (Male pseudo- 

 branchial rami not spirally twisted) S. cequiremis n. sp. 



8. The exopod of the uropods conspicuously overreaches the endopod. 



Abdomen without black lateral spots 9. 



9. Male pseudobranchial rami on second to fourth pairs of pleopods 

 spirally twisted. Distal joint of the exopod of the uropods not half 

 as long as the proximal and at most twice, frequently somewhat 



