192 



ZOOPHAGA. 



Shell spiral and enveloping ; aperture either canalieu- 

 lated or notched. 



TRIBE. CANALIFERA. 



With a longer or shorter canal at the base of the 

 aperture ; the outer lip not changing its form by 

 age. 



GENUS. CERITHIUM. 



Turreted ; the aperture oblong, oblique, terminated at 

 its base by a short canal which is either truncated 

 or recurved, never notched; a groove at the upper 

 part of the right lip ; a small horny, orbicular 

 operculum. 



C. COSTATUM. F. p. 357. STROMBIFORMIS C. 

 Da Cos. p. 118. t. 8. /. 14. STROMBUS C. Don. t. 

 94. Mont. p. 255. Lin. T. 8. p. 142. Dor. Cat. p. 

 46. t. 14. /. 14. D. p. 678. Turreted, dark brown, 

 with ten or eleven whorls furnished with numerous fine 

 close-set longitudinal ribs and an elevated spiral line 

 turning round the bottom of each volution and becoming 

 double at the base of the shell ; aperture suborbicular, 

 outer lip a little expanded, inner lip smooth, with a 

 short canal, t. Devon, Cornwall, rare. 



