92 Addison E. Verrill, 



3. Rostrum and ocular spines triangular or dentiform and equal or sub- 

 equal in size. 

 S. minus; brevicarpus. 



4. Telson much narrowed distally; the end very narrow, carrying only 

 four to six plumose hairs between the lateral spines. 

 S. goodei; longicarpus. 



5. Uropods with the outer lamella serrated along the distal outer margin. 

 S. goodei; longicarpus. 



6. Smaller chela with a large tuft or crest of porrect hairs on the outer 

 surface of the dactyl. 

 S. goodei; longicarpus; pectiniger.* 



7. Smaller chela with the tips of one or both fingers bidentate or tri- 

 dentate. 

 S. longicarpus; goodei; pcctiniger* 



8. Ambulatory legs with stout tapered dactyls, ending in two .unequal, 

 divergent hooks, the inner one more incurved, and with a blunt spur 

 or obtuse elevation proximal to inner hook. 

 S. hemphilli; fritsmullcri. 



9. Ambulatory legs have rather long gently curved dactyls and two 

 nearly parallel unequal hooks curved with the outline of the dactyl; 

 not divergent; no spur. 

 S. minus; brevicarpus; townscndi, 



10. Ambulatory legs with the dactyl short, incurved, and the two hooks 

 not very unequal, small, incurved. 

 S. goodei; longicarpus. 



II. Antennal scale notably wide; usually wider than spine. 

 v9. townsendi; minus; brevicarpus. 



12. Antennal scale narrow. 



S. fritzmullcri; hemphilli; goodei; longicarpus. 



13. Antennal scale rudimentary or lacking. 

 5". longicarpus. 



14. Basicerite spine unusually short, but with an acute, secondary spine 

 above its base. 

 S. hemphilli; fritsmullcri carolinensis. 



15. Basicerite spine without a secondary spine, or with only a short 

 or rudimentary one. 

 S. brevicarpus; longicarpus; townsendii. 



16 Basicerite spine elongated, with a small acute secondary spine. 

 S. minus; goodei; fritzmulleri. 



The above table is intended to be of use especially with specimens 

 that have lost their large chelae and more or less of the other 

 appendages; additional species will doubtless be found at the 



