CIDARIS BLUMENBACHI. 317 
that without the spines it could not be distinguished.* It 
is of a depressed form, and has very long subcylindrical 
spines ; a specimen is figured Lign. 102, fig. 9. It is this 
cidarite which occurs in such immense numbers in the Oolite 
at Calne, Chippenham, Faringdon, &c. Slabs of limestone are 
_ occasionally extracted from the quarries at Calne, with more 
than thirty of these echinites surrounded by thew spines. 
I have one specimen, attached to a block of limestone, with 
fifty spines ; but it is difficult to detach a perfect spine. 
Crparis BuumensBacuil. Lign. 127, fig. 3.—This is an- 
other beautiful characteristic Turban Echinite of the Oolite. 
_ The tubercles are very large and prominent, and the spines 
remarkably neat, being covered with longitudinal granulated 
striz ; they are of an elongated cucumerine form, and homo- 
geneous in structure (Lign. 127, fig. 5). They occur by 
hundreds in some of the layers of friable stone in the 
quarries around Calne. 
Many species of Turban Echinites abound in the White 
Chalk, especially near Gravesend, Northfleet, Purfleet, Charl- 
ton, and other places in Kent; the softness of the creta- 
-ceous strata in those localities rendering the removal of the 
chalk an easy task. Splendid specimens, with the spines 
and tubercles almost as fresh as if recent, have rewarded the 
patience and skill of collectors. The British Museum con- 
tains many fine examples, especially a specimen of Cidaris 
celavigera from Charlton, with sixteen spines, and the dental 
apparatus in situ. 
* Mr. Woodward. I am indebted to this gentleman for many 
valuable remarks on fossil Echinoderms. 
+ Several coloured figures of Cidarites and spines are given in 
Pict. Atlas, pl. lili. and lvi. A fine series of Chalk specimens are 
figured in Dixon's Fossils, tab. xxv.; many from the choice cabinet 
of Henry Catt, Esq. of Brighton. 
The collection of Chalk Cidarites with their spines, formed by 
W. H. Taylor, Esq. F.G.S., of Winterslow-place, Brixton, is the most 
splendid assemblage of these fossils I have seen. 
