CONCHOLOGY. 117 



5. Genus Planaxis. PI. XI. 

 Animal. Unknown. 



Shell. Ovate conical, solid ; aperture ovate, sublongitudinal, 

 columella flat and truncated at the base, separated from the right 

 margin b}^ a narrow sinus. Interior surface of the right margin 

 furrowed or lineated, and a callosity running under the summit. 

 Inhabits the American and W. Indian seas. Four species. 

 Planaxis sulcata. Planaxis bicolor. 



P. undulata. *P. Isevigatum. 



6. Genus Phasianella. PI. XI. 



Animal. Spiral ; foot oval ; upon each side an appendage 

 ornamented with filaments ; head edged anteriorly with a kind of 

 veil formed by a double, bifid, fringed lip ; two long conical ten- 

 tacula ; eyes borne upon short peduncles and situated at the ex- 

 ternal part of their base ; mouth between two vertical subcornate 

 lips. 



Shell. Marine ; many of them very rare and valuable ; their 

 beauty of colouring disposed so as to resemble the plumage of a 

 pheasant. Oval, rather thick, smooth and glossy, spine pointed; 

 columella uniting itself with the left edge, forming interiorly a 

 londitudinal callosity ; aperture oval, larger before, with edges 

 disunited ; operculum calcareous, oval, oblong, subspiral, the 

 summit at one extremity. Inhabits the British coast. Twelve 

 species. 



Phasianella varigata. Phasianella sulcata. 



P. rubens. P. angulifera. 



P. bulimoides. P. lineolatus. 



P. elegans. P. perdix. 



P. lineata. P. Mauritania. 



P. nebulosa. P. Peruviana. 



7. Genus Turritella. PI. XI. 



Animal. Spiral ; foot fringed anteriorly by a transversely 

 wrinkled band ; tentacular long, very fine towards their extremity 

 somewhat thick at their base, and having the eyes upon an inflation ; 

 the head skirted with a veil or fringe garnished with filaments. 



Shell. Turreted, not nacred, rather thin, striated in the direr 



