THE LAND AND FRESH- WATER MOLLUSC A OF ION A. 297 



examples of all of which have been submitted to 

 Mr. J. W. Taylor, F.L.S., Leeds, for confirmation, viz. : 



Limncea peregra (Miill.). — Common in a stream in 



the middle of the island. 

 Avion ater (L.). — Our common black snail. 



bourguinati, Mabille. 

 Limax agrestis, L. — The common pale-brown slug. 

 Vitrina pellucida, Miill. 

 Zonites cellarius (Miill.). 



alliarius (Miller). 

 Helix aspersa, Miill. — Found on the eastern side, 

 but also in some abundance on the faces 

 and in the crevices of the high shore 

 rocks on the western side, where it seemed 

 to be meditating hibernation. 

 nemoralis, L. — On both eastern and western 



sides. 

 hortensis, Miill. — On both eastern and western 



sides. 

 sericea, Miill. — Common, as stated, under 



stones on the eastern side. 

 ericetorum, Miill. — Abundant in most parts 



of the island. 

 rotundata, Miill. 

 Bulimus acutus (Miill.). — Plentiful. 

 Pupa umbilicata y Drap. 

 Cochlicopa lubrica (Miill.). 



Iona consists chiefly of schistose rocks of the 



middle Silurian period. It is one of the "Mid- 



Ebudes" (or central group of the Inner Hebrides) 



which form the British vice -county No. 103, and 



which, in addition to Mull, include Coll, Tiree, Ulva, 



and, in the words of Sir Walter Scott, 



" all the group of islets gay 



That guard famed Staff a round." 



