UNIVALVES. NAUTILUS. 51 



NAUTILUS Pearly Sailor. 



Animal— (vide Rumpf. Mus, tab. M.fig^ Bj Shell uni- 

 valvCf divided into several departmentSf communicat- 

 ing with each other by an aperture . 



This genuscontainsnolessthan thirty-one species. They 

 are nearly allied in point of general formation and struc- 

 ture, but the most prominent mark of distinction is, that 

 most of the species have their whorls divided into sepa- 

 rate compartments or chambers, which are connected by 

 a littletube or pipe (Syphon), which runs spirally through- 

 out the shell. This Syphon is sometimes central in the 

 shell, and sometimes contiguous to the surface. 



The Nautilus Pompilius, when bisected, exhibits in an 

 eminent degree the pearly concamerations for which this 

 genus is famous. The inhabitants of the East often con- 

 vert fine specimens of the above species into drinking cups, 

 whose surface they carve into various devices and orna- 

 ments; they also frequently remove the outer coating en- 

 tirely, and thereby bring the shell to a beautiful pearly 

 mass. The umbilicated varieties of this species are ac- 

 counted exceedingly scarce. 



The general form of the Nautili is mostly spiral or scroll- 

 like, some having their whorls contiguous, as the Pompi- 

 lius, Calcar, Crispus, &c. &c, and others having them de- 

 tached or separated, as the Spirula, Semilituus, Spengleri, 

 &c. &c. &c. But others, again, have a very different 

 formation, being tooth or funnel-shaped, almost like some 

 of the Dentalioe; such are the Fascia, Legumen, Obli- 

 quus, &c. &c. 



The size of the Nautili differs exceedingly; some are 



