EXPLANATION OF PLATES 43. 44. 63 



Plate 43. V. I. pp. 270, 271. 



Fig. 1. 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 in- 

 structive 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, showing at 

 a-, a 2 , a.3, the disposition of the lateral lobes. See 

 V. I. p. 271, Note. (Original.) 



Fig. 3. Cast of the interior of Nautilus Ziczac, in the col- 

 lection of Mr. James Sovverby, showing the disposi- 

 tion of the lateral lobes. (See V. 1. pp. 271, 272. 

 (Original.) 



Fig. 4. Cast of a single chamber of Nautilus Ziczac, in 

 the collection of Mr. J. Sowerby, showing the dis- 

 position of the ventral and dorsal Lobes and Siphun- 

 cle. See V. I. p. 271, Note. (Original.) 



Plate 44. V. I. p. 273, et seq. 



Fig. 1. Molluscous animal inclosing the Spirula Peronii. 

 See V. I. p. 273.* (Blainville.) 



Fig. 2. Section of a Spirula (Nat. size), showing its trans- 

 verse Plates and siphuncular sheath. (Original.) 



* M. Robert has recently discovered between the Canaries and 

 Cape Blanc, several imperfect bodies of a small species of molluscous 

 animal, each inclosing a Spirula. 



In all these the position of the shell is not at the posterior extremity, 

 as in the figure of the specimen found by Peron, but in the back, 

 parallel to the axis of the body, like the shell of the Sepiostaire, or 

 internal shell of the common Sepia. This position agrees with that of 

 the animal figured by Blainville, if we suppose the caudal portion of 

 the latter to have been lost. 



On each side of the body are two expansions that act like Fins, as 

 in the Sepiole. Beneath the neck is the aperture of the Funnel. la 



