SPINES OF CIDARITES. 319 
Spines oF Crparites. ign. 102.—Allusion has been 
made to the immense numbers of the spines of two or three 
kinds of Cidarites that occur in the oolitic limestones of cer- 
tain localities. The spines of other species and genera 
abound in the Chalk, Greensand, &c. ; occurring detached 
Lien. 102. Fossit SpixEs Or CIDARITES. 
Fig. 1.—Spine of AcrocrpaRiIs nobilis (Agassiz). 
2.— CIpDARIS cucumifera. 
3.— stemmacantha. 
meandrina. 
spinosa. 
clunifera. 
sceptrifera. 
Parkinsoni. 
HEMIcIDARIS intermedia. 
SLES 
Boeeee 
and intermingled with corals, shells, and the usual fossils of 
those deposits. There is great variety in the form, size, and 
sculpture of these organs. In the subjoined Zign. 102, a 
few distinct kinds are represented. 
