DESCRIPTION. 165 



variegated with scale-like spots of brilliant white ; 

 yellowish towards the margin, vertex white, lateral. 

 Inhabits Africa. 



Fig. 8. P. Graca. 



Shell ovate, convex; margin crenulate within. 



Lister Conch, Tab, 327. Fig. 1, 2. 



Specimen white, with ten dull red rays ; thick, 

 covered with decussate striae ; internally white and 

 smooth ; perforation oblong. 



Inhabits the shores of Europe. 



PLATE XXII. 



Fig. 1. Dentalium elephantinum. 



Shell with ten angles, somewhat bent, striate. 



Lister Conch. Tab, 547. Fig. 1. 



Specimen pale green, obscurely annulate on the 

 outside, with darker shades ; apex white ; within 

 smooth ; ribs projecting. 



Inhabits the Indian and European seas. 



Fig. 2. Serpula lumbricalis. 



Shell round, flexuous; apex spiral, acute. 



Lister Conch. Tab. 548. Fig. 1. 



