MOLLUSCA. SOLENOSTOMATA. 
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II. Shell turrited ; whorls suhconical, slightly embracing. 
1. BtrcciNiDiE. Shell truncated or rounded anteally; the canal 
scarcely produced beyond the anterior margin of the lip, and 
bent towards the left. 
2. Muricid^. Shell acuminated at the base ; the canal produced 
beyond the anterior margin of the lip, and either straight or 
bent. 
8. Cerithiad^. Aperture of the shell oblique ; canal short, trun- 
cated or recurved. 
4. STROMBUsiDiE. Outer-lip spreading with age, and having a 
notch or sinus near the commencement of the canal for the 
passage of the head. 
