149 



over these, the cidaris subangularis of Klein, and the echinus 

 angulosus of Lamarck, with one or two more of the La- 

 marckian genus echinus, are found. Here are also first dis- 

 covered remains of the genus clipeus : clipeus sinuatis of 

 Plot, and clipeus clunicularis, are here found in very good 

 preservation. These fossils afterwards occur in all the suc- 

 ceeding superior beds of the oolite series. 



Echinidal spines, of a long, acicular form, so well pre- 

 served as to retain traces of their original colour, are found 

 in the Stonesfield slate. 



In the cornbrash, and in the clay over the great oolite, 

 are found a very depressed conular echinus, which might, at 

 first sight, be mistaken for CI. sinuatus. The situation of 

 the mouth and vent would characterize it as a depressed 

 galerites, but that the petaloidal forms iti which its ambulacra 

 are disposed would place it rather among the clypeasters. 



Several species of cidarites also occur in the beds of the 

 oolite, and principally in the cornbrash, in the clay over the 

 great oolite, and in the upper beds of that rock. Three 

 beautiful species are found chiefly in the coral rag : — 1. Cid. 

 papillata, Organic Remains, Vol. iii. PL i. fig. 9, very closely 

 agreeing with that which is found in the chalk. 2. Cid. 

 intermedia. Organic Remains, Vol. iii. PL i. fig. 6. 3. Cid. 

 diadema, fig. 4 of the same plate. In this bed, the coral 

 rag, probably the last in which they occur, none having 

 been spoken of as found in any strata of posterior formation, 

 clipeus sinuatus, and clunicularis, are found in excellent 

 preservation. 



The green sand presents some very curious and inte- 

 resting facts respecting these fossils. In the waters which 

 deposited this formation, the spatangi appear to have first 

 existed, no remains of this genus having been discovered in 

 any of the subjacent formations. It is also deserving of 

 observation, that they are not found again but in the chalk, 

 and in the seas of the present world. These fossils, like 



