482 FOSSIL INVERTlEBRATED ANIMALS. 



been regarded as ammonites by Mr. Sowerby, under the names 

 of A. sphcericus and A, striatus. 



A very considerable number of species of fossil nautili, found 

 in England, and described and figured in the work of Messrs. 

 Sowerby, have been met with in the strata anterior to the 

 chalk, or in the most ancient strata of that substance. One 

 of these, the N. imperialis, from the Highgate clay, we have 

 figured. The coarse shell-limestone of the environs of Paris con- 

 tains some pearly specimens ; some of which have been referred 

 by M. Lamarck to Nautilus pompilius, which is found, in the 

 living state, in the great Indian ocean. M. de France has other 

 specimens in his possession, which he thinks may belong to 

 Nautilus umbilicatus, found at present in the same habitat. 



At Haudan, in the department of the Seine and Oise, 

 and at Dax, are the remains of a large species, {Nautilus 

 Deshayesii, De France,) which is very remarkable, because, 

 independently of its siphunculus being very near the last 

 whorl, and formed by kinds of funnels which enter one into 

 the other, each of its septae presents on either side a conical 

 depression, which ends in the direction of the siphunculus 

 against the interior paries of the sides of the shell, but which 

 does not communicate with the chamber which precedes. 



It is probably something similar to this which is found in 

 certain nautili above the siphunculus, near the last whorl, 

 which has given rise to the belief, that some species had two 

 siphunculi ; and on this character Denys de Montfort esta- 

 blished the genus Bisiphite. But an examination of those shells 

 which appeared to have two siphunculi seems to have proved 

 that this was a mistake. 



Nautili have been found in the fossil state in Italy, various 

 parts of France, Germany, and the Low Countries, &c. Some 

 of these shells are a foot and a half in diameter. 



In Eiffel, a canton of the duchy of Juliers, in the environs 

 of Chimay, and in some parts of Ireland, in very ancient 

 formations, fossil shells of several species have been found, 



