Plate XV. 



Page 

 Fig. I. Oceauapia robusta Bow. a oxea, b a developmental form, x 255, c sigmata, 



X 700 78 



— 2. Oceauapia robusta Bow. Radial section of the outermost part of the rind, 



X ca. 22; a the outermost layer with the projecting spicules — 



— 3. Oceauapia robusta Bow. Piece of the membrane surrounding the canals, with 



its skeleton, x ca. 60 — 



— 4. Oceauapia robusta Bow. The membrane lining the canals inmostly, with its 



spicules and cellules splieruleuses >, x ca. 60. (A piece from one of the larger 

 canaLs.) — 



— 5. Bieinina rosea Frstdt. a subtylostyli, b a developmental form, x 120, c head 



ends of different subt\'lostyli, x 380, d sigmata, more or less contort, x 485. . . 82 



— 6. Biemvia rosea F~rstdt. Dermal membrane from the pore side with projecting 



spicula-bundles, x ca. 32 — 



— 7. Bieinma rosea Frstdt. The surface seen from the oscular side with more or 



less open oscula and projecting spicula-bundles, x ca. 32 — 



— 8. Biemiiia rosea Frstdt. Piece of the transverse section from the pore side to 



about the middle, showing the columns supporting the skin, subdermal cavities, 

 and two large canals; the smaller canals are not given, x ca. 32 — 



— 9. Bieinma rosea Frstdt. Piece of a transverse section towards the oscular side. 



X ca. 32 — 



