Fig. l. Fragment of Nautilus sypho, in the collection of W. I. Broderip, Esq. from the Miocene division of the Tertiary formations at Dax, near Bourdeaux. The accidental fractures of this fossil afford an instructive display of the disposition of the transverse Plates and Siphuncle. (Original.)

Fig. 2. Another fractured shell of the same species from Dax, in the collection of Mrs. Buckland, shewing at a¹, a², a³, the disposition of the lateral lobes. See V. I. p. 359, Note. (Original.)

Fig. 3. Cast of the interior of Nautilus Ziczac, in the collection of Mr. James Sowerby, shewing the disposition of the lateral lobes. (See V. I. pp. 359, 360. (Original.)

Fig. 4. Cast of a single chamber of Nautilus Ziczac, in the collection of Mr. J. Sowerby, shewing the disposition of the ventral and dorsal Lobes and Siphuncle. See V. I. p. 359, Note. (Original.)