Plate IV. 



2, 3, 9, 14 17 Brissopsis lyrifera. I, 4, 13, 18 Br. elongata. 5, 19 Brissopsis sp. 6 8, 1012 Hemiaster expergitus. 



Fig. i. Brissopsis elongata, actinal side. '/,. 



2. lyrifera (Mediterranean), abactinal side. I / I . 



3. actinal side. I / I . 



4. elongata, abactinal side. I / I . 



5. sp. (Talisman), side view. J /i- 



6. Hemiaster expergitus, abactinal side. 1 / l . 



7. side view. 3-s/,. 

 8. actinal side, '/i- 



9. Brissopsis lyrifera (Mediterranean), side view. r /i- 



10. Hemiaster expergitus, abactinal side. s-s/,. 



ii. side view. I / 1 . 



12. actinal side, s-s/i- 



13. Brissopsis elongata, side view. I / I . 



14. lyrifera (Kattegat), side view. */f. 



15. (Kattegat), abactinal side. 1 / I . 



16. (Mediterranean), side view. I / I . 

 17. (Kattegat), actinal side. l / T . 



18. elongata, subanal fascicle and adjoining parts of the test. 2 j I . 



19. sp. (Talisman), actinal side. I / 1 . 



