Q6 Mr. W. E. CoUiiige on a new Species o/Arion. 



VII. — The Anatomy and Description of a neio Species oj 

 Arion. By Walter E. Collinge, Mason College, 

 Birmingham. 



[Plate V. A.] 



In July last I received from ]\Ir. E. W. Swanton, of Bratton 

 St. Maur, Wincanton, a series of slugs collected on a lawn at 

 Wainsgrove, Somersetshire, amongst which I noticed a small 

 Arion, which I informed Mr. Swanton was a young example 

 of Arion empiricorum^ Fer. On a closer examination, how- 

 ever, I was struck by the active way in which it crawled 

 about, the flatness of the back, and the manner in which it 

 elongated itself. After a few days it was killed by drowning, 

 and preserved in alcohol. Not until now have I been able to 

 make an examination of it internally, and it is at once evrident, 

 from the fully developed condition of the generative system, 

 that it is an adult slug, and from the morphology of the same 

 it can no longer be referred to A. empiricorum. 



Although I am acquainted with most of the members of 

 this genus and its allies, I am not aware of any species that 

 approach at all near to the one described below. I mention 

 this as, being described from only a single example, and 

 collected in a garden, it might possibly have been introduced 

 in the roots of foreign plants. Mr. Swanton has so carefully 

 worked the slug-fauna of Somersetshire, that I am somewhat 

 surprised he has not met with this species before. I have 

 examined all previous consignments of small Arions which he 

 has from time to time sent me, but find nothing approaching 

 it amongst them. 



Arion elongatus, sp. n. (PI. V. A. figs. 1-4.) 



Head and tentacles blackish, the latter slightly lighter than 

 the head. Centre of mantle marked with a pyriform mass of 

 deep black, bounded on either side by a narrow yellowish- 

 grey line, below by a deep black band which gradually shades 

 off into a yellowish grey. Whole of dorsal surface a deep 

 black, bounded, like the mantle, by a yellowish-grey line, 

 then a deep black band, which shades off" into a yellowish 

 grey. Foot-fringe yellow, with sepia lineoles. Sole 

 yellowish ; lateral jdanes distinct from median plane, which 

 laiier is marked in a dendritic manner and slightly lighter in 

 colour. Kug£e large and flat. Respiratory orifice distinct. 

 Keel absent, the back being almost flat. Length alive 24 

 millim. ; length in alcohol 15 millim. ; length of mantle in 



