Plate XVIII. 



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



2 o-lobiferous - — elcgans, from the inside. Obj. II. Oc. I. 



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



— 4. Tridentate pedicellaria of Echinus a/finis. Obj. o. Oc. o. 

 c _ — - — acutus. Obj. o. Oc. o. 



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



- tridentate - — var. norvegicics, from the inside. Obj. II. 



Oc. I. 



— 8. Spicules of Echinus tnelo. Obj. V. Oc. I. 



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

 io . — — - — gracilis. Obj. II. Oc. I. 



_ tI . _ — - Alexandri. Obj. II. Oc. I. 



— 12. Spicules of Echinus csculcntus. Obj. V. Oc. I. 



— 13. Valve of a tridentate pedicellaria, small form, of Echinus csculcntus. 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 a/finis. Obj. II. Oc. I. 



\- — — — - atlanticus. Obj. II. Oc. o. 



_ 18. — — - melo. Obj. II. Oc. o. 



_ IO/ . — — triphyllous - Alexandri (type-specimen). Obj. II. Oc. I. 



_ 20. — — tridentate - — csculcntus. Obj. II. Oc. o. 



_2i. — — — — - gracilis, large form. Obj. II. Oc. o. 



22. — - elcgans, from the inside. Obj. II. Oc. o. 



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



— 24. Globiferons 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. — — - elcgans, from the side. Obj. II. Oc. I. 



— 27. — - — lucid us. Obj. II. Oc. I. 



— 28. — — — - affinis. Obj. o. Oc. I. 





