77 



fomewhat lefs in breadth ; they are extremely compreHed, 

 with from twelve to fifteen vifible concamerations, the four 

 or five ladfepta only are raifed or elevated on the furface, 

 and thefe are a little wrinkled : aperture of the fyphon 

 nan'ow, fubcrenated, and placed at the outer margin clofe 

 to the canna. This Apjjenine extraneous fofiil has not we 

 believe ever been found in Englajid, either in that flate or 

 recent ; but it fliould feem to exifi in a living ftate in the 

 Adriatic, having been defcribed amongft the minute JVautili 

 obferved in the fediment of the fea, on the fliore o[ Rimini. 



FicHTEL has figured fcveral varieties of calcar, fome of 

 which are deflitute of carina, others are ftrongly carinated, 

 and even flioot into fpines on tliat part. If thefe can be admit- 

 ted as tlie fame fpecics, efpecially fig. d. e. f. Tab 1 2, we may 

 bid defiance to fpecific definition : but this able author is 

 not fingular in fuppofing the fpecies to be fo fickle in its habit. 

 Although we may diner in opinion with M. Fichtel in 

 this particular, wc cannot but ofter the tribute due for his 

 elegant work on minute J^uulilus, intitled " Tejlacea Mi- 

 crofcopica aliaque rninuta ex gcneribus Argonauta et JVautiiust 

 adjiaturum picfa et defcripta." It was the intention of this 

 able naturalifi to have divided the Linnaan JVautili into four 

 gaiera, under the titles JVautilus, Hammonium, Lituus, and 

 Orthocerus ; but we lament that other occupations will not 

 permit him to attend to the other three genera. 



Nautilus 



