DESCRIPTION OF THE PLATE. 



Fig. 1 — 9, Lepidopleurus africanus, nov. spec. 



Fig. 1, 2. The animal, seen frora above and from below. 



3. First valve, from above. 



4, 5. Second valve from above and front view. 



6, 7. Eigbth valve from above and from the right side. 



8. Sculpture of the central areas of the intermediate valve.s. 



9. A spicule of the integument, 375 X. 



Fig. 10 — 14, Ischnochiton rissoi Payr. and its affinities. 



10. A. Scales of Ischnochiton rissoi, 110 X- 



B. Spicule of the underside of the girdle. 300 X- 



C. Spicule of the margin of the girdle. 300 X- 



11. A. Scale of Ischnochiton me^ieghini and dautzcnbergi 110 X- 



B. Spicule of the underside of the girdle, 300 X- 



C. Spicule of the margin of the girdle, 300 X- 



12. Structure of an intei'mediate valve of Ischnochiton rissoi. 



13. Idem of Ischnochiton meneghini. 



14. Idem of Ischnochiton dautzenbergi. 



Fig. 15. Chito>i{Radsia)chierchiae, new spec. and Chiton (Radsia)goodalliBvo(i. 



15. First valve of Chiton (Radsia) chierchiae. 



16. Second valve of CJiiton (Radsia) chierchiae. 



17. Eighth valve of Chiton (Radsia) chierchiae. 



18. Different foi'nis of scales of Chiton (Radsia) chierchiae. 



19. Scale of Chiton (Radsia) goodalli from above and from the left side. 



20. Integument of Chiton (Radsia) goodalli. 



21. Idem of Cliiton (Radsia) chierchiae. 



22. Spicules of the undei'side of the girdle of Chiton (Radsia) chier- 

 chiae, 110 X- 



23. Chiton (Radsia) chierchiae, '/éi (^ region with small scales. 



24. Two portions of this region a ; a little enlai'ged. 



25. Scales of the girldle 30 X- 

 26-27. Scales of region a 30 X- 



28. Right ventral part of Chiton (Radsia) cliierchiae. 



F foot. A Anus, or i'enal opening, ug genital opening, Sch S'chleim- 

 krausen. 



29. Heart of Chiton (Radsia) ^^ooiUüli. Nat. size. 



30. ld. of Chiton (Radsia) chierchiae. Nat. size. 

 81. Radula of Chiton (Radsia) goodalli 30 X- 

 32. ld. of Chiton (Radsia) chierchiae 30 X. 



