In a communication to the Royal Society, in 1848, I demonstrated how utterly at variance with the facts were these conclusions, and pointed out the essential distinctive characters that separated the two extinct genera, so far as the specimens then discovered would warrant.[86] Other illustrative examples of the Belemnite have since been obtained; and in a supplementary paper read before the Royal Society, February 14th, of the present year (1850), I have stated what appears to me to be the extent of our present knowledge of the organization of the Belemnite. I subjoin an abstract of that paper, which embodies the result of an examination of many hundred specimens of Belemnites and Belemnoteuthites. The annexed outline, or diagram, shows the known structures of the Belemnite; of the soft parts of the animal, a few imperfect carbonaceous traces, apparently of the mantle, around and between the shelly processes of the upper part of the phragmocone, are the only vestiges I have been able to detect. The most perfect Belemnite hitherto discovered consists of, [Footnote 86: Philos. Trans. 1848, p. 171.] [Illustration] 1. An external _Capsule_ (_e_) which invested the osselet or sepiostaire, and extending upwards, constituted the external sheath of the receptacle. 2. The _Osselet_, characterized by its fibrous radiated structure, terminating distally in a solid rostrum or guard (_i_), having an alveolus, or conical hollow (_g_), to receive the apical portion of the chambered phragmocone, and expanding proximally into a thin cup, which became confluent with the capsule, and formed the receptacle (_b, b_,) for the viscera. 3. The _Phragmocone_ (_d_), or chambered, siphunculated (_c_), internal shell; the apex of which occupied the alveolus (_g_) of the guard, and the upper part constituted a capacious chamber, from the basilar margin of which proceeded two long, flat, testaceous, processes (_a, a_,). These structures comprise all that are at present known of the animal to which the fossil commonly called "_Belemnite_," belonged. Of the _Belemnoteuthis_, the cephalopod which Professor Owen considers to be a Belemnite, many examples of the body with eight uncinated arms and a pair of long tentacula, and with an ink-bag, and palleal fins, have been discovered. The osselet of this animal, like that of the Belemnite, has a fibro-radiated structure, investing a conical chambered shell; but this organ, for reasons fully detailed in the memoir, could never have been contained within the alveolus of a Belemnite. No _certain_ evidence has been obtained of the occurrence of an _ink-bag_ in natural connexion with a Belemnite. Diagram of the known Structures of the _Belemnites Puzosianus_, from Trowbridge. _a, a_, dorsal processes. _b, b_, the receptacle. _c, c_, the siphuncle. _d, d_, the phragmocone. _e_, the capsule. _f_, the inferior end of the phragmocone. _g_, the alveolus of the guard. _h_, vertical section of the guard.