38 JOURNAL OF CONCHOLOGY. 



THE BRITISH SLUG LIST. 



By W. DENISON ROEBUCK. 



[Read before the Conchological Society.] 



We take advantage of the preparation of a new list of 

 British moUusca to insert the names of such species and 

 varieties of slugs as it seems desirable to include, making at the 

 same time such corrections of nomenclature as will— without 

 causing confusion — tend to bring our list more in accord with 

 the present advanced state of limacology on the Continent. 

 We abstain from doing more, as a complete revision of the 

 nomenclature of this interesting group is not called for in a list, 

 where it would only bewilder the student accustomed to use 

 ' Jeffreys ' or ' Rimmer ' as his text-book. The subject has 

 during the past twenty years received a considerable amount of 

 attention at the hands of German, French, Italian and Swedish 

 malacologists, but in these kingdoms there does not appear to 

 have been a professed limacologist since the days of the Rev. 

 B. J. Clarke. It is consequently on his valuable papers that 

 most of the present additions to our list have been founded. 

 The writers of manuals of British mollusca have for the most 

 part ignored the variations of the slugs or treated the subject in 

 a careless inaccurate way. 



The most important modifications now introduced into the 

 list are the adoption of the genus Amalia for the two keeled 

 species of Limax, and the introduction of Limax cinereo-niger 

 Wolf, a form now recognised as a valid and distinct species by 

 all continental authorities. 



The varieties now brought forward — few in comparison 

 with those which further and more detailed study will bring 

 under our notice — are merely colour-mutations, and have 

 mostly been known as British for some time, though so far 

 without names. 



J.C, iv., April, 18S3 



