332 TROCHIDiE. 



the North Atlantic from Finmark and the Faroe Isles 

 to the Canaries, the Mediterranean, Adriatic, and 

 -^gean, at depths ranging between the shore and 60 f. 



The shell is subject to much variation in the height 

 of the cone, as well as in the number and size of the 

 ridges. Specimens procured by trawling on the Devon 

 coast are more than an inch and a half in length and 

 breadth; the smallest are from Guernsey. The fry 

 are slightly umbilicate, and the topmost whorl is reti- 

 culated. 



The spelling of the specific name has partaken of the 

 variability of the object designated. Zezyphinus, Zyzi- 

 phinus, Ziziphinus, and Sisyphinus are the readings pro- 

 posed by Chemnitz, Born, Montagu, and Macgillivray, 

 The last of these writers imagined that the name was 

 derived from the rolling stone of Sisyphus, and not 

 from Zizyphum, the fruit of the jujube-tree. 



This species is the T. conuloides of Lamarck, T. Cran- 

 chianus and T. irregularis of Leach, and Ziziphinus 

 vulgaris of Gray. Risso seems to have manufactured 

 half a dozen species out of it or of T. conulus. Cantraine 

 comprehended both, with a number of allied species, 

 under the name of T. polymorphus. The fry is probably 

 the T. parvus of Adams. 



^Vhether Philippi was right or wrong in uniting 

 T. zizyphinus mth T. conulus is a moot question ; but 

 there is not, in my opinion, sufficient evidence of the 

 latter species or form being British. Mr. Bean says 

 that many years ago his son took a living specimen 

 of it, attached to the sounding-lead, off the Lin- 

 colnshii'e coast, during his voyage in a collier from 

 Newcastle to London. It appears that the discoverer 

 had not long previously been in the Mediterranean, 

 where T. conulus is common on the shore at low water. 



