109 



The existence of these shells, in a fossil state, was known to Beccarius 

 and Plancus, who found them in considerable numbers in the moun- 

 tains not far distant from Rimini and Bologna. Plate XL Fig. 27, is 

 one of these fossil shells, brought from the Appennines, in the neighbour- 

 hood of Sienna, by Mr. Meacle. The matrix is a yellowish spathose 

 concretion. 



The reversed variety of this species, or, as it is in general considered, 

 the reversed species JV. beccarii reversus, is also found in considerable 

 numbers on the Appennines, along with the former. This reversed fossil 

 shell is represented Plate XI. Fig. 28. The opposite side of the shell is 

 here represented ; but, being of a reversed shell, it runs in the same 

 direction as Fig. 27. 



Among the minute shells which Plancus considered as recent Cornua 

 ammonis. were some which he distinguished as being bordered; since 

 many of them, especially those which were whole, possessed a wide pel- 

 lucid margin, which was spread round the whole shell. Whether all these 

 shells were naturally thus bordered, and lost this border by the violence 

 of the waves; or whether those which are bordered are of a distinct spe- 

 cies, he attempts not to determine. De Conch, min. notis, Cap. iv. 

 Similar shells have been found fossil in the hills of Bologna and of Pied- 

 mont ; and both the recent and fossil ones, he observes, are sometimes 

 found as large as small lupins. App. i. p. 85. 



One of these fossils, through the kindness of Mr. Meade, is repre- 

 sented Plate XL Fig. 30. It appears to accord very nearly with Nau- 

 tilus subarcuatulus, Supp. to Test. Brit. PL xix. Fig. 1, the separated con- 

 voluted portion of which had been taken for N. calcar. 



LXXIIL Spirula. A multilocular shell, partly spiral and partly 

 straight, the turns being disposed in a discoidal form, and separate 

 from each other; the last turn being elongated, and continued in a 

 straight line. The septa are transverse, regularly concave outwards, 

 and pierced with a shelly tube : the opening circular. 



This genus is very properly separated from Nautilus by Lamarck; 



