Antediluman Zoology and Botany. 279 
not to be passed unnoticed here; and, although it is capable 
of extension from later discoveries, it affords a copious illus- 
tration of the geological position of this numerous order 
in the English strata. These fossils existed most abundantly 
in the chalk. One genus, Ananchites, containing many spe- 
cies, is known only in this formation, and has not been per- 
petuated in our present seas. 
Echini, of the genus Cidaris, first appear in the lias, but 
unfrequently. In the lower oolite several species abound, and 
the green sand is also rich in them. The crag contains a 
species from this genus. Mr. Parkinson notices that one 
genus, Spatangus, appears first in the green sand, and then 
in the chalk ; that it is absent in all succeeding formations, but 
that it is found again, living in the seas of the present world. 
co] fo) 
Mr. Phillips, however, has observed Spataéngi much lower, 
having traced the same species im the calcareous grit, the 
coral rag, and Kelloways rock. 
Ananchites. Galea ovata? A group of casts in flint from chalk, Norwich. 
TESTACEOUS MOLLU‘SCA. 
Shellfish. — For convenience of arrangement, we separate 
this division into simple univalves, simple bivalves, ancient 
complicated bivalves, and multilocular or chambered uni- 
valves. From the first class some naturalists have withdrawn 
the tubular shells, to form a fifth under the head of Annulosa ; 
and even further subdivision has been made by other classi- 
fiers; while, again, in another case, the whole have been 
comprised in three classes, the Annelides, the Conchifera, 
and Mollisca. 
