MONOGRAPH OF BRITISH LAND AND FRESHWATER MOLLUSCA. 2cS5 



Family ARIONID^ Gray. 

 Genus ARION F6russac. 



Dr. Simroth suggests that a more satisfactory basis for the classification 

 of this group might be afforded by the diiferences in the length of the 

 epiphallus, an organ which seems to possess great constancy in this respect 

 in the various species. 



The external markings on the body are directly connected with the 

 circulation of the blood, and the lyre-shaped marking on the shield is 

 coincident in form with the lung, which lies beneath in the form of a ring. 

 As the dark markings on the mantle are dependent on the circulation of 

 the blood during the respiratory processes, one may conclude that the 

 dark markings on the side-areas are used for skin respiration. This is 

 probably, however, less likely in the larger species, on account of their 

 thicker skin and greater secretion of coloured slime, so that the correla- 

 tion of circulation and markings is not so marked. 



Arion ater (L.). 



Food and Habits. — Young Arion ater are often found on Allium 

 ursinum in the neighbourhood of Leipzig. 



Var. aterpima Taylor. 

 The name of aterrima has been objected to, as having been previously used by 

 Dumont and Moitillet, but this is not so, as those authors do not appear to have 

 described any variation under that name. 



Var. castanea Dum. & Mort. 



ENGLAND AND WALES. 



Kent W.— Sub- var. fusco-lutescenx, Chislebursb, T. D. A. Cockerell. 



Berks.— Unhill Wood near Streatley, July 1906 ! Rev. E. Peake. 



Ang-Iesey— Sub-var. brunnea, common, Cemmaes, July 1895 (C. Oldham, Journ. 

 of Conch., July 1898, p. 86). 



Lancashire S.— Sub-var. brunnea, near Oldham (F. Taylor, Journ. of Couch., 

 April 1898, p. 49). 



York S.E. — Sub-var. brunnea, Aldborough, T. Petoh. 



IRELAND. 

 Antrim— The Manse, Antrim, Sept. 1904 ! W. S. Smith. 

 Armagh— Sub-var. brunnea, Forkhill, Jan. 1904, and Armagh, Feb. 1904, P. H. 



Grieraon. , t. tt /-, • 



Louth— Sub-var. brunnea, near Carlingford, P. H. Grierson. 



Meath— Sub-var. brunnea, Bective Abbey, March 1905 ; Moynalty and Kells, 

 April 1905, P. H. Grierson. „ ,t ^ • 



Wicklow— Sub-var. brunnea, Greystones, Sept. 1903, P. H. Grierson. 



Galway W.— Dernasliggan, April 1897, R. Welch ; this locality is erroneously 

 stated to be in East Gahvay (p. 178). Type and sub-var. brunnea, abundant. 

 Gentian Hill, July 1895 (Collier and Standen, J. of Conch., April 1896, p. 178). 



Galway E.— Killinure, Lough Ree, Sept. 1906, R. Standen. 



Clare- Near Limerick, Sept. 1904 ! G. J. Fogerty. 



Var. plumbea Roebuck. 

 ENGLAND. 

 Sussex W.— Near Liphook, July 1905, Rev. S. Spencer Peaic^e. 

 Derby— Rowsley (Lionel E. Adams, Journ. of Conch., vii., p. 77). 

 York Mid W.— Addingham, Aug. 1906 ! F. Booth. Grass A\ood, Grassington, 

 Sept.' 1906 ! S. Hainsworth. 



