CERITHIUM. 197 



is deeply and abruptly sinuated at the suture ; its course is 

 at first straig-litish, but abruptly rounding at the base it 

 advances so as to overlap and close up the sides of the 

 canal. The pillar is very solid, dark coloured, short, 

 rounded, and furnished with a padlike reflection of the 

 inner lip. The throat is quite smooth. The length of 

 a large example was scarcely four lines and a half; 

 the breadth was not quite one-third of this measure- 

 ment. 



A figure of Delle Chiaje, apparently representing this 

 species, shows rather a short snout and thick tentacula, a 

 rather long triangular foot, bearing a multispiral operculum. 

 Loven gives an account of the animal of the genus Triforis 

 drawn up apparently from this shell. He describes it as 

 having a broad short head ; long, cylindrical slender ten- 

 tacula with subclavate tips, their bases remote but con- 

 nected by a sinuated veil ; eyes very shortly pedunculated 

 (placed on bulgings) at their bases ; operculigerous lobe 

 single ; mentum (fold in front of the foot) distinct ; siphon 

 short ; operculum paucispiral, with a nearly central nucleus. 

 In the present state of our knowledge we are unwilling to 

 separate it from Cerith'mm. 



More common in the south than in the north, but 

 diffused with a westerly distribution from the Channel 

 Isles to Zetland. It ranges from the Laminarian zone 

 to as deep as fifteen and twenty fethoms ; sometimes 

 deeper. The localities for it are so generally those of other 

 British Cerithia that the same enumeration will suffice : in 

 the main it is scarcer. Very seldom taken alive : so rarely 

 that we have never but once succeeded in obtaining it in a 

 living state, and then on a rock at low water, in the 

 Channel Islands, although dead and broken shells were 

 abundant in neighbouring localities (S. H.) 



