SPONGIIDA. 
23 Spong. 
Bulben ; described and figured by Carter, (14) p. 212, pi. xiv. b, figs. 8, 9, 
10-13 & 17. Other doubtful spicules also found, figs. 14-lG. 
Sollas, (17) p. 393, assigns various spicules and fragments of fibre from 
Chalk flints, Norfolk, to Hexactinellid sponges of the Dictyonina group. 
Hexactinellid anchoring spicules, in flint, (15) p. 72, pi. i. figs. 31-36, 
pi. V. fig. 27. 
Spicules from flint with borings produced by some living organisms, 
(15) p. 73, pi. V. figs. 28 & 29. 
G. W. Giimbel, Verb. geol. Reichsanst. 1880, p. 213, states that he has 
found specimens of Flysch rock from various localities to consist chiefly 
of sponge-spicules ; sandstone, limestone, and marl alike contained them ; 
agglomerated globular forms occurred among others ; some shaly Neo- 
coraian rocks are similarly constituted, also the black Lias shales of the 
Southern Alps. 
G. C. Wallich, “A Contribution to the Physical History of the Creta- 
ceous Flints,” J. G. Soc. xxxvi. p. 68, concludes that sponges supplied the 
obviously large amount of protoplasm and organic silex which occurred 
at the sea bottom in the Chalk period. 
