HARDWICKE'S SCIENCE-GOSSIP. 



55 



showing, with an assiduity which of itself commands 

 the highest praise, the variations to which the species 

 belonging to their special group are liable, and they 

 are doing this not only from this one point, but, 

 taking their distribution in space into consideration, 

 they are prosecuting their labours to the utmost in 

 order to reduce all these variations down to the 

 causes that have produced them. And it has occurred 

 to me that in working out the etiology of these 

 variations there would be great aid rendered were 

 the general distribution, both of themselves and of 

 the type-forms, taken into account, and especially so 

 where the geological formation of the several countries 

 has been fully worked out. For this reason this 

 paper has been written ; and, in order to make it the 

 more useful to collectors in this country, I have 

 described in full all the named varieties of the slugs 

 that are indigenous to this country, those that have 

 as yet been recorded as British being denoted by an 

 asterisk. And for those especially working at the 

 slugs, I have appended a bibliography for further 

 reference. 



Arion ater, Linn. — This slug is generally dis- 

 tributed over the Continent, ranging from Norway 

 over France (particularly in this country it occurs in 

 the north and centre) and Germany to Spain, Corsica, 

 Italy, Sicily, and even into Africa and the islands of 

 Madeira and the Azores. Its varieties with their 

 distributions are as follows : — 



Var. virescens, Mull. : animal greenish, with two 

 lateral bands of an orange-yellow colour ( = A. vi- 

 rescens, Mull.). French. 



Var. rubra, Moq. : animal reddish or dull red, 

 unicolor. French. 



Var. Draparnaudi* , Moq. : animal dark red, foot- 

 fringe yellowish or reddish. Also French. 



Var. succinea*', Mull. : animal yellowish, unicolor 

 (= L. succineus, Mull.). Also French. 



Var. bicolor* (V.-Broek), Moq. : animal dark 

 brown, sides yellowish or orange. (This variety has 

 been recently found at Louth by Mr. Wallis Kew.) 

 Also French. 



Var. nigrescens*, Moq. : animal blackish, foot- 

 fringe reddish or yellowish. Moquin describes this 

 variety as French, and Locard has recorded it from 

 Dauphine and the Savoy. 



Var. marginata* , Moq. : animal black, foot-fringe 

 yellow, orange, or of a red-lead colour. French. 



Var. Miilleri, Moq. : animal black, keel pale 

 greenish. French. 



Var. pallescens *, Moq. : animal dirty white, a little 

 reddish or yellowish. Also French. 



Var. albida*, Roebuck : animal white, unicolor. 

 Not yet recorded for any other country but England. 



Var. rtifa*, Linn. : animal red or brownish, uni- 

 color {— L. ricfus, Linn. ; " Syst. Nat." edit. x. 

 1758, p. 652). Also French. 



Var. albolatcralis *, Roebuck : animal dark brown 

 or blackish, with the sides white and the foot-fringe 



orange ; the two last colours being very sharply 

 defined from one another. (This beautiful variety, 

 which was described in 1883, is only known from 

 North Wales and Sussex.) 



Var. pallescens *, Roebuck : animal light yellow. 

 This variety is closely identical with var. succinea, 

 Mull., and ought perhaps to be associated with it. 



Var. cinerea, Westerl. : animal ashy, with three 

 lateral pale black bands. Scandinavian. 



Var. grisco-?)ia)-gi?iata, Dumont and Mortillet : ani- 

 mal pale blackish, foot-fringe grey. Locard found 

 this variety in the woods of Mount Saxonnet at 1000 

 metres altitude. French. 



Var. nigra *, Dumont and Mortillet : animal black 

 or blackish (= type). 



Var. aterrima, Dumont and Mortillet : animal en- 

 tirely black (= type). 



M. Mabille records Arion ater from the following 

 French districts, which show well the distribution of 

 this species in that country : La Seine, Champagne, 

 Haut-Rhin, Haute-Garonne, Agenais, Var, Dau- 

 phine, Hautes-Pyrenees, Lozere, Ariege, Aude, 

 Savoy, the Oriental Pyrenees, and the Vosges. 



Arion flavus, Miill. — This is a very doubtful 

 species. Moquin-Tandon in his " Histoire naturelle 

 des Mollusques de France," records three varieties as 

 French, viz.: — 



Var. normalis, Moq. : animal yellow, head and 

 tentacles black. 



Var. pallida, Moq. : animal pale, back slightly 

 ashy, mantle yellow. 



Var. albida, Moq. : animal whitish, mantle and 

 sole of foot yellowish, tentacles blackish. 



Arion hortensis, Fer. — This, the garden slug, 

 is a generally distributed species, both in England 

 and on the Continent. 



Var. dorsalis, Moq. : animal grey, with a black 

 band on mantle and back. French. 



Var. leucophaca, Moq. : animal bluish-grey, striped 

 and spotted with black. French. Drouet records 

 this from Troyes, and Normand from Valenciennes. 



Var. fasciata*, Moq.: animal grey, black bands. 

 Also French. 



Var. nigra, Moq. : animal black, with lateral grey 

 bands. French. 



Var. Pyrena'ica, Moq. : animal deep grey, with a 

 blackish band on each side. Locard took this at 

 Luchon. French. 



Var. grisea *, Moq. : animal pale grey, unicolor. 

 Also French. 



Var. limbata, Moq. : animal black or blackish, foot- 

 margin orange or pale yellow. French. 



Var. alpicola, Moq. : animal reddish-grey, black 

 bands. French. Charpentier found this variety on 

 the Alps. Found also by Lessona on the Lombardian 

 and Piedmontese Alps. 



Var. rufescens *, Moq. : animal reddish, black 

 bands. Also French. 



Var. subfusca, Pfeiff. : animal brownish, with a black 



