LINN.EAN GENERA. 17 



Third Division : 2 sections. — 1st. Univalves 

 with a regular spire : 14 genera. 



Argonauta, paper-sailor, ex. A. argo. 

 Nautilus^ sailor, ex. N. pompilhis. 

 Conus, cone, ex. C. Hehrceus. 



* CyprcBci, cowry, ex. C. moneta. 



* Bulla, dipper, ex. B. naucum. 



* Vohita, wreath, ex. V. utriculus. 



* Buccm9/m, whelk, ex. B. reticulafum. 



* Stromhus, screw, ex. S. pes-pelicani. 



* Mure.v, rock-shell, ex. M. ramdsus. 



* Trochus, top-shell, ex. T. hifaciatiis. 



* Turho, wreath, ex. T. muricatus. 



* Helios, snail, ex. H. nemoralis. 



* Neihta, nerite, ex. N. striata. 



* Haliotis, ear-shell, ex. H. tuherculata. 



2d Section, without a regular spire : 5 genera. 



* Patella, limpet, ex. P. vulgata. 



* Dentalium, tooth-shell, ex. D. elephantinum. 



* Scrpnla, worm -shell, ex. S. triquetra. 

 Teredo, ship-worm, ex. T. navalis. 



* Sahella, Sabella, ex. S. Belgica. 



Total number of genera in the arrangement of 

 Linnaeus, thirty-six. 



The genera marked with an asterisk, contain 

 species found in Britain. 



