.256 DR. HINDE AND ME. HOLMES ON SPON&E-EEMAINS 



EXPLANATION OF THE PLATES*. 

 Plate VII. 

 Figs. 1,2. Acerate spicules of Reniera or Chalina. X 2U0. 



3-8. Acerate spicules of Eeniera or Chalina. V\g&. 3, 7, 8 X 200 ; fig. 4 



X 100; fig. o X 300. 

 9, 10. Elongate acerate spicules. X 100. 

 11-13. Abruptly pointed acerate spicules. Figs. 11, 13 X 200; fig. 12 

 X 100. 

 Fig. 14. Fusiform tibiella spicule. X 200. 



15. Spinecl acerate of Halichondria ? X 200. 



16. Spinecl acerate. X 300. 



17. Verticillately spined acerate. X 200. 



18. Spined acerate of iJa^ic/^oMifrw? X 200. 

 Figs. 19, 22. Curved spined acerates. X 200. 

 Fig. 20. Spined acerate. X 200. 



21. Annulated acerate spicule. X 200. 

 Figs. 23-25. Acerate spicules with central inflation. Fig. 23 X 300; figs. 24, 



25 X 100. 

 Fig. 26. Acerate spicule, with spines in centre, of Alectona ? X 300. 



27. Spined subcylindrical spicule. X 200. 



28. Verticillately spined subcylindrical spicule. X 200. 



29. Verticillately spined subcylindrical. x 200. 



30. Spined cylindrical spicule. X 200. 



Figs. 31-36. Smooth cylindrical spicules of Eeniera ? Figs. 31-35 X 200 



fig. 36 X 100. 

 Fig. 37. Dumb-bell spicule of Plocamia. X 200. 



38. Subcylindrical spicule, with spiral ridges, of Botona ? x 200. 



39. Spined dumb-bell spicule of Plocamia. X 200. 



40. Spined cylindrical spicule. X 200. 



41. Spined acerate spicule. X 200. 



Figs. 42, 43. Spined subcylindrical spicules of Ht/meniacidon ? X 100. 



Fig. 44. Spined acerate spicule of Alectona. X 200. 



Figs. 45, 47. Smooth cylindrical spicules of Baspailia ? x 200. 



Fig. 46. Smooth cylindrical spicule of Eeniera ? X 100. 



Figs. 48-50. Smooth fusiform, tibiella spicules of Myxilla ? Figs. 48, 49 



X 100 ; fig. 50 X 50. 

 Fig. 51. Cylindrical spined spicule o^ Plocamia "i X 200. 

 52. Vermiculate spicule of Axinella. X 200. 



Plate VIII. 

 Fig. 1 . Tibiella spicule of Myxilla ? X 200. 



2. Elongate tibiella spicule of Forcepia ? X 200. 

 Figs. 3, 4, 5. Different forms of tibiella spicules. Fig. 3 X 100 ; fig. 4 X 200 ; 



fig. 5 X 300. 

 Fig. 6. Tibiella spicules with spined ends of lopkon ? X 200. 

 7- Smooth acuate spicule. X 100, 



* To assist in the preparation of the Plates the Authors received a grant from 

 the Eoyal Society, which they desire hereby to acknowledge. 



