2 Spong. 
XVII. SPONGIER. 
Page 
D. Bionomics.18 
(i) General Accounts.18 
(ii) Special Habits . 18 
(iii) Habitat ..18 
(iv) Defence and Protection . . . . . 18 
(v) Enemies.. 18 
(vi) Commensals and Parasites.18 
(vii) Sponges as Geological Agents, Fossilization . 18 
e. Reproduction, Development, and Growth . . . 19 
(i) Germ-Cells, Fertilization.19 
(ii) Embryology.19 
(a) General Accounts.19 
(b) Early Stages, Larvae, and Metamorphosis 19 
(c) Post-Larval Development, Organogeny . 19 
(iii) Asexual Reproduction . . . . . . 19 
(a) Fission and Vegetative Budding . . 19 
(b) Germinal Budding and Gemmule-For- 
mation.19 
(c) Regeneration ...... 20 
f. Miscellanea ......... 20 
(i) Technique ..20 
(ii) Economics ........ 20 
(iii) Bibliography..21 
(iv) History......... 21 
(v) Folk-lore, Popular Notions.21 
III. Distribution. 
a. Geographical . . . . . . . . . 21 
a. Marine .......... 21 
(i) General......... 21 
(ii) Atlantic Ocean and Adjacent Seas ... 21 
(iii) Indian Ocean and Adjacent Seas ... 22 
(iv) Pacific Ocean and Adjacent Seas ... 22 
(v) Arctic Seas ........ 22 
(vi) Antarctic Seas ....... 22 
ft. Freshwater ......... 22 
(i) Europe ......... 22 
(ii) Asia ......... 22 
(iii) Africa ......... 22 
(iv) Australian Region . . . . . . 22 
(v) America ........ 22 
b. Geological.23 
(i) General ........ 23 
(ii) Cainozoic ........ 23 
(a) General ....... 23 
(b) Pleistocene ...... 23 
(c) Pliocene ....... 23 
(d) Miocene ....... 23 
(e) Oligocene ....... 23 
(f) Eocene ....... 23 
