An attentive examination of Belemnites has enabled me to ascertain their zoological characters, and to distinguish between the different species which have been discovered more precisely than has yet been done. The result of this examination I have now the pleasure of laying before the Geological Society; but before I proceed to describe the characters of these fossils, it will be interesting to notice the various opinions which have at different times been entertained respecting them. We may indeed derive some useful hints from ancient names and traditions, as pointing out the countries in which particular fossils are found, and hence obtain some knowledge of the strata occurring in the places to which such traditions refer. I. Geological Position of Belemnites, and a Sketch of the Opinions that have been entertained respecting their Origin. The geological position of Belemnites is in the lias and in the strata above it, as high as the chalk inclusive. None have ever been found in beds older than the new red-sandstone on the one hand, nor on the other in any of the formations above the chalk. They also occur frequently detached and bouldered among gravel and alluvial soils, the compactness of their substance having preserved them from complete destruction. In the beds to which they belong they occur in association with the remains of marine animals, and are so frequently met with that it is evident they were by no means rare in the seas in which they lived. The term Belemnite is