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118. 
119. 
120. 
BRITISH FOSSIL SPONGES. 
1872 Soutirer, C. A. Ueber die Spongitarien-Baenke der oberen Quadraten 
und unteren Mukronaten-Schichten des Miinsterlandes (Sitzwngsb. 
d. Niederrhein. Gesells., pp. 1—88, Pl. 1). 
Describes in detail the characters and stratigraphical distribution of the 
various Sponges in these beds, and constitutes two new genera of hexactinellid 
Sponges, Lepidospongia and Becksia. 
1873 Satter, J. W. Catalogue of Cambrian and Silurian Fossils in Geol. 
Museum, Cambridge. 
The forms referred to Sponges are placed under Amorphozoa. It is stated 
“that Stromatopora, Coscinopora, Cnemidium, Verticillopora, Stellispongia, &c., 
are examples of very solid calcareous Sponges. Ischadites, Spherospongia, 
Amphispongia, and other Silurian forms, are supposed to be distantly allied to 
the hving Grantia.” Ischadites Kenigii is figured erroneously with stem and 
roots. 
1873 Carter, H. J. On the Hexactinellide and Lithistide (Ann. and Mag. 
Nat. Hist., vol. xii, p. 349, 437, Pls. xii, xvii). 
Refers in detail to the spicular structure of these groups as shown in 
existing species, and comparisons are made in one or two cases with fossil 
forms as well. 
. 1873 Fisner, O. On the Phosphatic Nodules of the Cretaceous Rocks of 
Cambridgeshire. 
Refers to their constitution, and regards many of them as having originally 
been Sponges. 
2. 1873 Sonnas, W. J. On the Ventriculitee of the Cambridge Upper Green- 
sand (Quart. Journ. Geol. Soc., vol. xxix, pp. 63—70, Pl. VI). 
Describes the minute structure of the Ventriculite skeleton, which is stated 
to consist of the “regular anastomosis of a number of hexaradiate elements, 
each of which consists of six radial fibres, apparently tubular, diverging from 
a common centre, at right angles to each other.” The constitution of these 
fibres is not stated, but the author mentions that he failed to find spicules, 
either in silicified or phosphatised Ventriculites. The silicified Ventriculites 
are regarded as instances of the silicification of highly decomposable animal 
matter, and the phosphatic Ventriculites ‘are striking examples of the phos- 
phatisation of soft-bodied animals.’ The presence of siliceous Xanthidia and 
Polycystina in the Coprolites is adduced as ‘an argument against regarding 
the Ventriculites as having originally had a siliceous skeleton which had sub- 
sequently been replaced by phosphate of lime.’ ” 
