23 16 Proceedings of the Royal Irish Academy. 



Agriolimax agrestis L. — Abundant in all parts of the island, except on the 

 moorland. The prevailing form is of a unicolorous brown, but that with 

 reticulated markings was also frequent. The var. lilacina, which is 

 frequent on Achill and the Curraun promontory, occurred near Portlea, 

 as well as two jet-black specimens. 

 A. laevis Mull. — Frequent over the low-lying parts of the island, and found 

 also on the moorland surrounding Creggan Lough, as well as upon the 

 slopes of Knocknaveen. 

 Milax gagates Drap. — Common at the west end of the island, and occurs also 

 along the southern and south-eastern shores. Several almost jet-black 

 specimens were noted, and the tan-coloured form was taken in the Abbey. 

 The var. plumbea is the prevailing form. 

 Vitrina pellucida Mull. — Decidedly rare, though odd specimens were taken 



in most parts of the island. 

 Hyalinia cellaria Mull. — Common in the Abbey, and taken sparingly in the 

 ditches near the Pound, and along the south shore between the 

 Harbour and the Abbey. All the specimens are referable to Vitrea 

 hibcrnica Kennard. The shells from the Abbey were all of the opaque, 

 white form, var. rnargarituceu Schmidt. 

 H. alliaria Miller. — The most generally distributed species of the genus, and 

 shares with P. rotundata and Z. cxcavatus the claim to be the commonest 

 shell on the island. All specimens are of the large, dull, flat, western 

 form, and in colour range from the type to opaque white or green. This 

 western form appeal's referable to Westerlund's var. anceps, found in 

 Sweden. 

 H. nitidula Drap. — Except upon the cliffs of Croaghmore, this shell was 

 decidedly rare, though it was noted also on Knocknaveen and along the 

 south and north-east coasts. All examples have the suddenly expanding 

 and drooping aperture characteristic of the H. nitens of Michaud. 

 H. pura Alder. — Not nearly so common as the next species, but both type 



and var. nitidosa are frequently to be found. 

 H. radiatula Alder. — Type and the green form are equally common in most 



parts of the island. 

 H. crystallina Mull. — Generally distributed, but not common. Most specimens 



appear referable to H. contractu Westerlund. 

 Euconulus fulvus Mull. — Common in most parts of the island, but full-grown 



shells were seen only on the north-east cliffs and on Croaghmore. 

 Zonitoides nitidus Mull. — Extremely local and rare. Observed only in a 

 damp spot above Lighthouse Cove, and with S. p/eifferi along the margin 

 of the stream at the harbour-, 



