BIBLIOGRAPHY. 43 
230. 1885 Hinpn, G. J. On Beds of Sponge-remains in the Lower and Upper 
231. 
bo 
Greensands of the South of England (Phil. Trans. Roy. Soc., Pt. I, 
pp. 403—453, Pls. 40—45). 
Strata of chert and siliceous rock areshown to consist mainly of various forms 
of detached spicules of siliceous Sponges. These spicules principally belong to 
tetractinellid and lithistid Sponges, but monactinellid and hexactinellid Sponges 
are also represented. The spicules are figured and described, and reference is 
made to the changes produced in their structures by fossilization. 
1882-1885 Vosmarr, G.C. J. Porifera (Bronn’s Klassen und Ordnungen des 
Thier-Reichs, Lief. 1—11). 
The work mainly treats of recent forms. The Porifera, fossil and recent, 
are divided into two classes: (1) Porifera calcara, and P.non-calcarea. In this 
latter are included (Order 1) Hyalospongiz (= Hexactinellida) ; (2) Spiculi- 
spongie (= Lithistide, Tetractinellide, Myxospongize, Monactinellide, pars) ; 
(8) Cornacuspongiz (= Monactinellide, pars, Ceratospongie).  Zittel’s 
classification is mainly followed in the subdivisions of the fossil forms. 
. 1885 FeistmanteL, Kart. Spongien-Reste aus silurischen Schichten von 
Béhmen (Sitzungsb. d. Kénigl. bohms. Gesell. d. Wiss. in Prag. Jahrg. 
1884, p. 100). 
Records the occurrence of detached complete six-rayed hexactinellid 
spicules, in cherty rock of Lower Silurian (Cambrian ?) age in various localities 
in Bohemia. . 
