198 JOURNAL OF CONCHOI.OGY, VOL. I3, NO. 7, JULY, I9II. 



terists will only adopt some other name than the former for the beetles. 



Buccinum undatum L. — Alderney, common on the shell-beach, 

 and often large (Marquand) ; Guernsey, two small live specimens 

 dredged (Tomlin). 



This is a most instructive species, no other affording better evidence 

 of the effects of environment. Any one interested in the variation of 

 species will find the study of this one most fruitful and interesting, 

 while a series from various localities and depths will impart a good 

 object lesson in the variability of species. These variations and 

 mutations are without end, and all graduate one into the other. The 

 form, texture, size, sculpture, etc., appear to depend entirely on 

 habitat, and an experienced collector can readily tell, from the appear- 

 ance of the specimen, the nature of the sea-bottom and the probable 

 depth from which it had been procured. The Rev. Prof Gwatkin 

 gives the radula of Buccinum a very bad character as a help to specific 

 distinction ; he writes me that "the radula varies so much in Buccinum 

 that I consider it, for that family, worthless as a character, the indi- 

 vidual variations being greater than the specific." Herr Friele, of 

 Bergen, has also studied this subject exhaustively throughout various 

 species oi Buccinum and Fusus, and has arrived at practically the same 

 conclusion.^ He found that different species, and even different 

 genera, so interchanged and resembled one another, as to be useless 

 as a guide to the determination of species. He further corroborated 

 and supplemented these views in his later work on the results of the 

 Norwegian Arctic Expedition. 



B. undatum is very scarce in the Channel Isles except at one part 

 of Jersey facing the French coast, and I have never met with a speci- 

 men from the other islands ; it is equally scarce in the Scillies. But, 

 like Littorina littorea, B. undatum has of late years been coming into 

 the Jersey shell-fish market in some quantities from the opposite ports 

 of France, and the dead shells are to be found everywhere. These 

 French specimens are small and immature, and of sub-littoral origin. 

 Pure white specimens occur occasionally, but they are rare. 



var. flexuosa Jeff. — Very variable in size and texture, sometimes 

 attaining a length of S^in. in the West Orkneys and off Wick, while 

 a small thin form lives in the former district and in the Shctlands with 

 the var. zetlandica, and has the same silky epidermis. 



var. littoralis King. — The interior of this variety is sometimes 

 orange-coloured, but more frequently purplish-brown. 



var. paupercula Jeff. — Specimens from Southampton Water do 

 not exceed an inch in length ; many are smaller. 



I Jahrb. Deutsch. Mai. Ges., 1879, vol. vi. , p. 257. 



