FOSSILS OF THE CORNER ASH. 
117 
Serpula intestinalis ... ... PL V. fig. 21. Scarborough, common, 
quadrata... ... ••• ••• ••• Newton Dale. 
It is not so much by the presence of particular species of fossils which 
are found in no other stratum, that the cornbrash can be accurately iden- 
tified from Somersetshire to Lincolnshire, as by the occurrence together 
in it of some fossils which are repeated in rocks above, and several others 
which are found in those beneath. For, in the preceding list of thirty- 
seven species obtained from this stratum in Yorkshire, neaily two-thirds 
are certainly known to be repeated in other rocks, and possibly this 
proportion may be increased by more scrupulous researches. But this 
circumstance, whilst it confirms the inferences, derived from other con- 
siderations, of the general analogy among all the members of the oolitic 
formations on this coast, does not prevent the employment of zoological 
characters, to discriminate the cornbrash from its associated rocks, though 
it certainly demands a caution in their application, which is not always 
observed. 
Several fossils not peculiar to the cornbrash, as millepora straminea, 
pinna cuneata, amphidesma securiforme, and a. decurtatum, unio pere- 
grinus, vermicularia nodus, and ostrea Marshii, seem to be repeated only 
in the lower oolitic formation, and the large variety ? of modiola cuneata, 
melania vittata, and perhaps pecten demissus, have yet been found only 
in the upper oolite formation ; whilst the remains of echinida and pen- 
tacrinus, mya literata, sanguinolaria undulata, trigonia clavellata, pecten 
fibrosus, trochus granulatus, terebra granulata, and melania Hedding- 
tonensis, are common to both these formations, either in Yorkshire 
or in other parts of England. The cornbrash is the only conchiferous 
stratum in the eastern part of Yorkshire in which belemnites are 
particularly rare, and it seems at present to be the only repository of 
clypeus orbicularis, isocardia minima, cardium citrinoideum, plagiostoma 
rioidulum, terebratula ovoides, and t. digona, ammonites Herveyi, and 
a. terebratus. But though these shells should eventually be discovered 
in other strata, the cornbrash may still be discriminated in any local dis- 
trict, and satisfactorily identified in distant countries. By its clypei. 
