288 Mr. H. J. Carter on known Fossil Sponges. 
to a copy of Prof. Schulze’s Report on the ‘ Challenger’ 
dredgings of the Hexactinellida. 
Lastly, we come to my eighth order, viz. the CALCAREA; 
and here, again, we have to fall back upon the masterly re- 
searches of Professor Zittel, coupled with those of his intelli- 
gent pupil Dr. G. J. Hinde—the former to be found in the 
Abhandl. der bayer. Akad. W. ii. Cl. xiii. Bd. ii. Abth., and 
the latter in Dr. Hinde’s ‘ Catalogue of the Fossil Sponges in 
the British Museum,’ p. 157 &e. Referring to Prof. Zittel’s 
observations on the “ Occurrence, Distribution in Time, and 
Pedigree” of the Calcispongiz (translation ‘Annals,’ 1879, 
vol. ii. pp. 875-378), we learn, from the tabular view given 
at p. 378, that, so far as is known, they at least date from the 
Devonian period, are already numerous in the Triassic, increase 
rapidly in the Jurassic, and culminate like the Lithistida in 
the Cretaceous, after which isolated spicules only have been 
found. 
At first (like all who attempt to generalize from insufficient 
data) I was inclined to think, from the small delicate forms 
and rapidly decomposing nature of the British species, that 
it was impossible they could be subjected to the ordeal of 
fossilization without disappearing altogether; and if this had 
been the case generally I might have been right; but when I 
found that Prof. Zittel had demonstrated the reverse, by 
proving to me, from actual slices of what he considered to 
be fossil calcareous sponges, that they possessed the peculiar 
radiate spicules of a Calcisponge, and when, from the charac- 
ters of the South-Australian sponges of the present day 
which Mr. Bracebridge Wilson, of Geelong, kindly sent me 
(‘ Annals,’ 1886, vols. xvii. and xviii. p. 503 &c.), I could 
acquiesce in this from recent specimens, the absurd notion 
inferred from the characters of the British representatives of 
this order could no longer be entertained. Meanwhile 
several specimens from the Coral Rag (Jurassic system) of 
Farringdon, in Berkshire, from which I made as many micro- 
scopically thin slices, fully justified Prof. Zittel’s announce- 
ment. 
Furthermore, Dr. Hinde, in his “ Notes on Fossil Calci- 
spongie”’ (‘ Annals,’ 1882, vol. x. p. 185, pls. ix. and x.), 
describes not only specimens of his Verticillites d’ Orbignyt from 
the Greensand at Warminster, in which the radiate spicules 
could be seen with,a simple lens in abundance on the surface, 
but a new species of Sestrostomella from the Upper Greensand 
of “ Vaches Noires,”’ near Havre, in France (8. rugosa, H.), 
in which he found the “ tuning-fork ’’-like form of spicule that 
characterizes a recent species which Mr. Bracebridge Wilson 
