194 Scientific Proceedings, Royal Dublin Society. 



mantle is about one-third the lengtli of the body, and tbe mucus, 

 or slime, secreted by the slug is always milky. In A. Icevis on the 

 other hand, the mucus is colourless, and the mantle is about one 

 half the length of the body. 



Two species of Amalia occur in Ireland. This genus is charac- 

 terized, besides the granulated mantle, by the possession of a horse- 

 shoe shaped groove on the front portion of that part of the body. 

 The two species A. carinata (Leach.) and A. gagates (Drap.) are 

 not easily recognised, but the former secretes always a very viscid 

 mucus, while that of the latter is watery. A. carinata is generally 

 of a rich brown colour with a yellowish foot, while in A. gagates 

 the foot is white and the general body colour is, as a rule, lead 

 gray, but some times a very light drab. 



Of the genus Arion, five species have been found in Ireland up 

 to the present. Their external differences will be more easily 

 represented in a tabular form, and the following may be considered 

 a rough and ready synopsis of their external characteristics, but I 

 must mention that in some cases only anatomical investigation 

 will decide a doubtful point of identity. 



(A.) Margin of foot with transverse stri» = A. ater, A. subfuscus. 

 I. Wrinkles keeled and elongated = A. ater. 

 II. Wrinkles flat and short = A. subfuscus. 



(B.) Margin of foot without transverse striae = A. hortensis, A. Bour- 

 guignati, A. intermedius. 



I. Foot coloured = A. hortensis, A. intermedins. 



a. Wrinkles flat = A. hortensis. 



b. Wrinkles with conical spikes = A. intermedius. 



II. Foot white = A. Bourguignati. 



The last genus, GeomalacuSy is the most interesting of all the 

 Irish genera, as it combines in some respects the characters of the 

 genera Arion and Limax. Moreover, as I have mentioned before, 

 it is only found in the two most western points of Europe. 



Only one species of Geomalacus is found in Ireland, G. macu- 

 loms. It is a dark gray slug, covered with white or yellowish 

 spots. Like Limax, it has a hard internal shell, but, on the 

 other hand, the pulmonary aperture is situated in the front portion 



