Whelks and Conelets 253 



crossed by swollen, sometimes prickly ribs, which are 

 broken by a series of spiral channels. The colouring 

 is a flesh tint with touches of reddish brown. The 

 mouth is small and ends in a long anterior canal. 

 The operculum is pear-shaped, with the nucleus at 

 the narrow end. It has been found chiefly on the 

 shores of Devon, Cornwall, and Guernsey, in the Isle 

 of Man, Tenby, Dublin Bay, Cork, etc., in soft ground 

 between 15 and 50 fathoms. The Ribbed Spindle- 

 shell (T. truncatus) is broader, slightly more glossy, 

 and paler, the ribs not broken into tubercles by 

 the spiral grooves. The upper part of the spire is 

 smooth and polished, the mouth oval and the canal 

 short. It affects hard ground from 2 to 50 fathoms 

 deep, on the east coast, around Scotland, south and 

 east Ireland, and the Isle of Man. The Berwick 

 Spindle - shell (T. harvicensis) is more like the 

 Prickly Spindle but broader, much more glossy, the 

 whorls crossed by fewer but more prominent, almost 

 toothed, ribs. The cusps on these ridges are stronger 

 above, so that the top of the whorl appears to be 

 encircled by sj^ires. The colour is white. This is a 

 more northern form, occurring on stony ground from 

 low w^ater to 50 fathoms on our northern coasts, 

 coming only as far south as Yorkshire and North- 

 umberland. 



The Sting-winkles (Ocinebra) have the same form 

 of shell, but it is disguised by the ribs and great 

 thickening of the lip from time to time. What are 

 known as varices or " growth lines " really represent 

 periods of comparative rest from shell production. 

 At least, the shell is not enlarged internally, but only 

 thickened at its mouth. These are, of course, the 



