COLLINGE : STRUCTURE AND AFFINITIES OF EUROPEAN SLUGS. 115 



Italy, is subject to great variation. Accompanying the above were 

 examples of the variety fasciis-obsoktis, from the Vallie du Cervo 

 Piemont. 



Arion fuscus, Miiller, 1774. 



Locality : Vegesach bei Bremen. 

 " Beyond that this form is much smaller than A. subfuscus, Drap., 

 and has the lateral bands darker and more prominent, I fail to see 

 why it is separated from that species. The differences in the 

 anatomy of the reproductive organs — which are the only ones — are 

 but slight, and certainly not such as would justify it to rank 

 as a species. 



Var. stabilei, Pollonera. 



Locality : Maccugnaga, Val Anzasca, Piemont. 

 This form was described as a distinct species by Pollonera in 

 1885, 3 but later was very rightly relegated to varietal rank. 4 



Arion citrinus, Wester. 



I have not seen examples of this species, but from Westerlund's 

 description 5 I think it is only a variety of the A. fuscus, Mull., 

 without the lateral bands. I shall esteem it a great favour if some 

 malacologist will favour me with a few examples for dissection. 



Arion rubiginosus, Baudon, 1S68. 

 Locality : St. Saulge, France. 



Unfortunately these specimens were not in a suitable condition 

 for anatomical examination. Probabiy allied to A. subfuscus. 



Arion celticus, Pollonera. 



Locality : Brest, France. 



These agree externally with the specimens I have previously 

 examined from the South of England." I have made repeated 

 examinations of the anatomy of this form, and from the variable 

 nature of the same, I feel it is impossible to regard it as a good 

 species. Pollonera thinks that the differences in the reproductive 

 organs and lingual ribbon are sufficient to separate it from A. hortensis, 

 Fer. ; but even were these differences constant, which I have not 

 found to be the case, they are so slight that I think it better to 

 regard it as a variety of A. hortensis, as I have done with a form 

 varying in a similar manner, viz., the variety cceruleus, Cllge. 7 



■'■ Elenco moll. ter. Piem., p. 28, Atti Ace. Sc. Torino, 1885. 



4 Specie nuove o mal conosciente d. Avion europei, Ibid. p. 15, 1886-7. 



3 Expos£ crit., 1 871, p. 35. 



6 Conchologist, 1892, ii., p. 77. 



7 Ibid. p. 26. 



