32. 
we) 
NI 
38. 
BRITISH FOSSIL SPONGES. 
1839 Bronn, H.G. Letheea geognostica. 
In this work the followimg genera of fossil Sponges from Oolitic and 
Cretaceous strata are stated to possess an internal fibrous reticulated structure, 
Scyphia, Tragos, Mammillopora, Cnemidium, Myrmecium, and Hippalimus. 
Some of these genera are supposed to include horny Sponges, both recent and 
fossil. 
. 1839 Hacenow, F. v. Monographie der riigenschen Kreideversteierungen 
(Neues Jahrb., p. 260). 
The Sponges are placed with Corals and Polyzoaas Polyparien. Species of 
Achillewm, Manon, Scyphia, and Siphonia are named, and references given. 
. 1889 Mourcuison, R. I. Silurian System. 
Names and gives a figure of Ischadites Kenigii (p. 697, Pl. xxvi, fig. 11). 
Its affinities are considered very doubtful. 
. 1840 Rommer, F. A. Die Versteimerungen des norddeutschen Kreidegebirges. 
Numerous species of Sponges, many of them new, are described. They 
are for the most part placed in the meaningless genera, Spongia, Achillewm, 
Manon, Tragos, Cnemidium, and Scyphia. The new genus Plewrostoma is 
constituted. The descriptions are very brief and indefinite, and regard chiefly 
external characters. The minute spicular structure of many hexactinellid 
Sponges is described as lattice-shaped fibre and distinctly figured, but these 
Sponges are included in the same genus with lithistid and calcisponges. 
. 1841 Minster, Grar zu. Beitriige zur Petrefacten-Kunde. 
Numerous species of Calcisponges from the St.-Cassian beds are described 
and figured. ‘They are regarded as polyps and placed in the genera Achilleum, 
Scyphia, &e. 
. 1842-44 Konrnex, L. ps. Description des Animaux fossiles dans le terrain 
carbonifere de Belgique. 
Describes as a new genus of Corals, Mortiera ; a biconcave siliceous fossil, 
composed of thin lamelle. It is now regarded as a Sponge (P. 12, 
Bl; feo). 
1842 Bownzrgann, J. S. On the Spongeous Origin of Moss-agates and other 
Siliceous Bodies (Aun. and Mag. Nat. H., vol. x, pp. 9, 84, Pls. 
i—iil). 
The fibrous appearances in sections of moss-agates are stated to be due to 
the presence of keratose Sponges, and the chert of the Greensand strata and 
the flints from the Chalk are believed to have been produced by the continued 
attraction and solidification by keratose Sponges of the silex in solution in the 
ocean. 
