18(3 



To our worthy friend Mr. Boys, of Sandwich, we are 

 greatly indebted for the knowledge of many of this curi- 

 ous genus : by whofe affiflance we have been able to iden- 

 tify moft of thofe given by Walker, in his Tejlacea mi- 

 nuta rariora. 



I. 



Beccabii. Nautilus Beccaril. Lin. Syft. p.ll62.—GmeL Syji. p.3370.4- 



Turt. Lin. iv. p. 306.— Planch, t. 1. f. 1, 

 IValk. Min. Shells, f. 63.— Favan. t. 69 . D. 1 / 

 Martini Conch, i. t. 19. f. 178. 179.— t. 20. 

 f. 175. to lll.—Gualt. t. 19. f. H.H.I. 

 Adams Microfc. p. 640. t. 14. f. 29. 



N. with four, or five volutions; with deep fulcated 

 joints ; ten in the firfl fpire: upper part convex : beneath 

 flat, and the markings lefs diftinft : mouth turned down- 

 wards, not clafping the body whirl : aperture a fmall per- 

 foration in a convex front: in this part, however, it ap- 

 pears to be fubjeft to variation; for in fome we have ex- 

 amined, the front, or part in which the fyphon is placed, 

 has been depreffed or concave. 



The colour is frequently pellucid white, but more com- 

 monly covered with a brown epidermis ; this, however, 

 depends on the fituation in which ti.ey are found: when 

 the animal is alive, the pellucid fpecimens appear of a 

 crimfon colour. 



Found frequent on the Fucus vejiculofus, and on the 

 roots of other Algce, as well as on Oyjters and other (hells : 



and 



