74, 
75. 
76. 
78. 
a9. 
BIBLIOGRAPHY. 15 
Jurassic strata of St. Claude is described and the presence of canals in the 
axes of the spicules is noted, and their resemblance to the Ventriculites of 
Toulmin Smith is pointed out. This siliceous skeleton is stated to correspond 
to the horny skeleton of living Sponges, and cannot be compared to the 
spicules of existing forms. 
1860 D’Eicuwatp, EK. Lethzea Rossica, vol.i, p. 325. 
Describes species of Scyphia, Siphonia, Thoosa, and of several other 
genera, but judging from the characters and the figures it is very doubtful 
if any of the forms are genuine Sponges. 
1860 Rormer, Ferp. Die Silurische Fauna des westlichen Tennessee. 
Describes in greater detail than hitherto various species of Astylospongia, 
also proposes the genus Paleomanon for cup-shaped Sponges with the same 
spicular structure as Astylospongia.  Astreospongia is regarded as a Calci- 
sponge. 
1861 Owen, R. Paleontology, pp. 5—8. 
Sponges are placed under the class Amorphozoa and brief reference is 
made to their distribution in British strata. Calcareous Sponges are stated 
to abound in the Oolitic and Cretaceous strata, attaming their maximum 
development in the Chalk. No reference is made to the structure of Ventricu- 
lites or of Guettardia. Siphonia and the allied genera, grouped together as 
Petrospongiade, are stated to possess a stony reticulated frame without spicules 
and to have passed away with the Secondary epoch. 
1861 Gentz, H. B. Die animalischen Uebereste der Dyas, pp. 123, 124, 
Ply DEX: 
Refers to two species of Spongia some fossils of doubtful character, and 
copies the descriptions given by King of the reputed Sponges from the 
English Permian. 
1861 Covrtitter, A. Hponges fossiles des Sables du Terrain Crétacé supérieur 
des environs de Saumur (Ann. de la Soc. Linn. de Maine-et-Loire, 
4° vol., pp. 1—26, Pls. I—XL). 
Numerous species are described and referred to various genera. Only 
their superficial characters are noticed, and the species have thus little, if any, 
value. 
1861 Rormer, Furp. Die fossile Fauna der silurischen Diluvial-Geschiebe von 
Sadewitz. 
Several new species of Astylospongia are described ; the spicular structure 
of the genus is stated to consist of very regular six-rayed, star-shaped bodies, 
so united together that the rays of one star are intimately united with those 
