PLATE IV, 



Fig, 



1. Cythere concinna} Carapace of female (variety) seen from left side, 



2. — — „ „ above. 



3. — • — „ „ below. 



4. — — „ ■ „ front. 



5. — ■ — Right valve of female carapace, seen from outside. 



6. — — Left valve of male carapace, seen from outside. 



7. — — Carapace of male (variety), seen from left side. 



8. — — „ valves separated and seen from 



above. 



9. — — Carapace of female, seen from left side. 



10. — — „ valves separated and seen from above. 



11. — — ■ Carapace, seen from left side, male ; normal form. 



12. — — „ „ „ variety. 

 13 — 16. — Carapace in different stages of growth. 



17. — — Young carapace, seen from left side. 



18. — — ,, above. 



19. — — „ below. 



20. — — „ front. 



21. Cythere angulata? Carapace of female, seen from left side. 



22. — — „ above. 



23. — — „ ■ „ below. 



24. — — „ „ front. 



(All magnified 40 diameters.) 



At page 160, 1st line,/or Figs. 1 — 16, read figs. 1 — 20, 

 2 „ 162, 22nd „ for „ 17—24, read „ 21—24. 



