Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/358

 been seen in our English chalk. But research has not been made with the necessary precision.

Three Vermiculites. The fossil figured Org. Rem. vol. III. pl. VII. fig. 11, was considered as a vermiculite, until by removal of the chalk and opening different specimens it was found to be a chambered and an adherent shell. Should these gentlemen not have perceived these circumstances in the specimens they met with, they would certainly regard this fossil as a vermiculite. It must also be observed that from the different forms in which the spiral part is disposed, its division into two or three species might be authorised.

Belemnites. These, according to M. De France, are different from those which accompany the ammonites of the compact limestone. The belemnites of our chalk are smaller than those of the limestone, besides which they are different in form, being narrower and more elongated. But M. De France may also have confounded with them the spines of the echinus, which so closely resemble the belemnites if that gentleman should trot have met with perfect specimens, he might not be able to remark the difference between these two fossils. The characters which he has noticed are however sufficient to lead to the belief of a correspondence between the French and English fossils.

Fragments of a thick shell of a fibrous structure. The doubts expressed respecting the nature of this shell, and the observations made with regard to it, offer another strong point of agreement between the shells of the two strata. The shell here alluded to is most probably that represented Org. Rem. vol. III. pl. V. fig. 3; the structure of which agrees exactly with that mentioned as found in the French stratum of chalk. That shell is however described as being of a tubular form; it is therefore right to observe, that fossil pinnæ do sometimes possess this peculiar structure.