Plate XVIII. 



Fig. i. Valve of a tridentate pedicellaria of Echinus acutus, var. norvegicus, from the side. Obj. II. Oc. I. 



2. globiferous elegans, from the inside. Obj. II. Oc. I. 

 - 3. side. Obj. II. Oc. I. 



4. Tridentate pedicellaria of Echimis affinis. Obj. o. Oc. o. 



5. acutus. Obj. o. Oc. o. 



6. Valve of a globiferous pedicellaria of Echinus acutus, from the side. Obj. II. Oc. I. 



7. tridentate var. norvegicus, from the inside. Obj. II. 



Oc.I. 



8. Spicules of Echinus me.lo. Obj. V. Oc. I. 



9. Valve of a globiferous pedicellaria of Echinus Alexandri (The type-specimen). Obj. II. Oc. o. 



10. gracilis. Obj. II. Oc. I. 



- ii. Alexandri. Obj. II. Oc.I. 



- 12. Spicules of Echinus esculentus. Obj. V. Oc. I. 



13. Valve of a tridentate pedicellaria, small form, of Echinus esculentus. Obj. II. Oc. o. 

 14. Spicules of Echinus acutus, var. Flemingii. Obj. V. Oc. I. 



15. Valve of a tridentate pedicellaria, small form, of Echinus gracilis. Obj. II. Oc. I. 



- 16. globiferous of Echinus affinis. Obj. II. Oc. I. 



17. atlanticus. Obj. II. Oc. o. 



18. melo. Obj. II. Oc. o. 



19. triphyllous Alexandri (type-specimen). Obj. II. Oc. I. 



20. tridentate esculentus. Obj. II. Oc. o. 



- 21. gracilis, large form. Obj. II. Oc. o. 



- 22. elegans, from the inside. Obj. II. Oc. o. 



- 23. Alexandri, from the inside. Obj. o. Oc. I. 



- 24. Globiferous pedicellaria of Echinus acutus, var. norvegicus. Obj. o. Oc. I. 



25. Valve of a tridentate pedicellaria of Echinus Alexandri, from the side. Obj. II. Oc. I. 



26. elegans, from the side. Obj. II. Oc. I. 

 27. lucidus. Obj. II. Oc. I. 



28. affinis. Obj. o. Oc. I. 





