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BIBLIOGRAPHY. Halk 
1848 Romer, Ferp. Ueber eine neue Art der Gattung Blumenbachium, 
Koenig, und mehre unzweifelhafte Spongien in Obersilurischen 
Kalkschichten der Grafschaft Decatur im Staate Illinois in Nord 
America (Leonhard u. Bronn’s Neues Jahrbuch, pp. 6880—686, Pl. TX). 
Recognises the similarity in the nature of the spicules of Blumenbachium 
meniscus (now Astreospongia) to that of living siliceous Sponges. Undoubted 
Sponges from the Silurian strata (Niagara group) of North America are 
compared with Cretaceous Sponges and placed in the genus Siphonia. Sub- 
sequently the author placed these forms in a distinct genus, Astylospongia. 
1848 M‘Coy, F. On some new Mesozoic Radiata (Ann. and Mag. Nat. Hist. 
2nd ser., vol. ii, p. 397). 
Describes the superficial characters of four species of Cretaceous and 
Oolitic Sponges. No figures are given. 
1848 Mantett, G. A. Wonders of Geology, 6th edition. 
In this edition various species of Sponges from the Chalk and Greensand 
are figured, and referred to in general terms as Sponges and Zoophytes. 
Ventriculites is still stated to have been contractile. 
1848 CHariteswortH, EH. On the Mineral Condition and General Affinities of 
the Zoophytes of the Chalk at Flamborough and Bridlington (Proc. 
Yorks. Phil. Soc., vol. i, p. 73). 
These Sponges are apparently regarded as haying been originally of a 
horny character, and attention is called to the fact that their tissues are now 
sihcified. The different species named by Phillips are believed to be merely 
modifications of a single form, for which the author proposes the name 
Rhizospongia polymorpha. 
1849-52 D’Orsicny, A. Prodrome de Paléontologie. 
The Sponges are placed under Amorphozoa, numerous genera and species 
are introduced, but the characters given are so brief and indefinite that, in 
the absence of figures, it is impracticable to recognise them satisfactorily. 
1850 Kine, W. Monograph of the Permian Fossils (Pal. Soc., pp. 11—14, 
Pl; 2). 
Refers some doubtful organisms to the genera Scyphia, Mammillopora, 
Tragos, and Bothroconis, n. g. Only their external characters are described. 
1850 Dixon, F. Geology and Fossils of Sussex. 
Some specimens and polished surfaces of Siphonia in flint are figured, 
but nothing is stated of them beyond the fact that they are Sponges. 
