FOSSIL SPONGES. 
Spong. 23 
by R. Etheridge in an address on the analysis and distribution of the 
British Paleozoic fossils, J. G. Soc. xxxvii. [1881] pp. 51-235, and by id. 
op. cit. xxxviii. pp. 59-236, in an address on the analysis and distribution 
of the British Jurassic fossils. 
J. Badcock, Nature, xxv. p. 529, notices the invariable association of 
a red colour in certain chalk-flints from Surrey with the presence of 
Sponge skeletons, which are here coated with iron oxide ; the iron 
appears to be derived from the Sponge itself, either as metal or oxide. 
New Genera and Species. 
See Steinmann, supra. 
Barroisia , Munier-Chalmas, Bull. Soc. Geol. (3) x. p. 425. Based on 
Tubipora anastomosans. Mantell. Differs from Verticillites , Defrance, in 
the absence of the tubes which cross the chambers and subdivide at the 
point of contact with the upper plates. 
Stromatocerium richmondense, Miller, (19) x. p. 41, pi. ii. fig. 1, Hudson 
River Group, Richmond, Indiana. 
Dystactospongia , id. 1. c. p. 42. Based on D. insolens, sp. n., p. 43, pi. ii. 
fig. 2, Hudson River Group, Cincinnati. 
Patter sonia, id. 1. c. p. 43. Based on P. difficilis , sp. n., id. 1. c. pi. ii. 
fig. 3, Hudson River Group, Cincinnati. 
Verticillites d’orbignyi [dorbignii], Hinde, (18) p. 192, pis. x. figs. 1, 2, 
7, & 8, xi. figs. 1-24. The fibre is composed of filiform triradiates, with 
the third ray aborted ; most of the spicules resemble those of recent 
Leucones. Upper Greensand, Warminster. 
Corynella rugosa , id. 1. c. p. 196, pis. x. fig. 4, xi. fig. 25, C. socialis, 
id. p. 197, pi. x. fig. 3, both from same deposit and locality as the preced- 
ing. Filiform fibre-spicules occur in these species also. 
Sestrostomella rugosa , id. 1. c. p. 198, pis. x. fig. 6, xii. figs. 1-15. It 
appears to have the felted uni-axial spicules which occur on the 
surfaces of some recent Leucones ; the radiate spicules closely resemble 
those of Leucones. S. clavata , id. 1. c. p. 201, pis. x. fig. 5, xii. figs. 
16-25, like the preceding, from the Cretaceous formation near Havre. It 
exhibits essentially similar structures. 
Leptophragma ramosum , Nova Acta Ac. L.-C. Nat. cur. xlii. p. 23, pi. i. 
figs. 1-5, Plocoscyphia eggeri, p. 24, pi. i. figs. 6-8, Astrocladia furcata , 
p. 25, pi. i. figs. 11-14, C. Gerster, from Chalk near Passau. 
