Plate XII. 



Page 

 Fig. I. Rciiiera sp. b. Oxeum, x 255 50 



— 2. Reniera sp. c. Oxea, x 255 50 



— 3. Reniera Voeringii Ldbk. Oxea, x 255 50 



— 4. Metschnikowia spinispicukmt Cart. Spined strongyla, a fully developed, b an 



older and a younger developmental form, x 255 52 



— 5. Petrosia crassa Cart. Oxea, a of the larger ones, b of the smaller ones, c short 



oxea, strongyla and styli, x 255 54 



— 6. PhlcBodictyon tuber n. sp. Oxea, a fully developed, b developmental forms, x 255 57 



— 7. Phlceodictyoii tuber n. sp. Section of the skeleton vertical on tlie surface, 



showing lamellae, a the outer surface, x ca. 32 — 



— 8. PhlcEodictyon elongatuiit Tops. Oxea, a fully developed, b developmental forms, 



X 255. c end of oxeum, x 485 59 



— 9. Phlceodictyon eloiigatuni Tops. The dermal layer, seen from the outside, a pro- 



jecting spiculum is seen, x ca. 100 — 



— 10. Phlceodictyon irregulare n. sp. Oxea, a fully developed, b developmental forms, 



X 255 61 



— II. Geliius arcoferus Vosni. a oxea, x 165, b toxa, fully developed and younger 



forms, X 380, c sigmata, x 485 62 



— 12. Geliius angulatus Bow.? a oxea, x 165, b ends of different oxea, x 485, c toxa 



of different sizes, x 485, d sigmata, x 485 63 



