GENUS XXIV. BUCCINUM. 113 



Terebra. Shell turrited ; the aperture with a hollow at the 

 base, and about one-third of the length of the shell ; the 

 base of the pillar twisted or oblique (see Buccinum rna- 

 culatum, f. 81). 



DoLiuM. Shell swelled, nearly globular, with circular ribs ; 

 the right lip crenated or toothed its whole length ; the 

 aperture oblong, very large, with a hollow at the base 

 (see Buccinum Dolium, f. 82). 



Harpa. Shell oval or ventricose, with longitudinal sharp 

 ribs ; the aperture oblong, large, with a hollow at the 

 base, and no canal ; the pillar smooth, ending in a point 

 (see Buccinum Harpa, f. 83). 



Cassis. Shell ventricose; the aperture longitudinal, terminating 

 at the base in a short canal bent towards the back of the 

 shell ; the right lip margined outwardly ; the pillar with 

 folds at the lower end (see Buccinum cornutum jun., 

 f. 84). 



