THE NAUTILUS. 101 



most carefully, I discovered two specimens of Succinea avara Say 

 under a board in a swamp. On Little Cranberry Island, under 

 boards near the woods, I found : 



Cochlicopa lubrica Mull. Agriolimax compestris Binn. 



Vitrea hammonis Strom. Pyramidula striatella Anth. 



Euconulus fulvus Mill I. Succinea avara Say. 



With the exception of the places where the board-walk was be- 

 ing repaired, land shells were the most plentiful on great Cranberry 

 Island. The island is shaped like the letter G and is about four 

 miles long. I explored the western part of the island or the back of 

 the G most carefully. The western shore is composed of ledges of 

 solid rock behind which lies an extensive bog. Where the rock 

 wall is low the surf has built " sea walls " by piling up cobblestones, 

 making a steep beach back of which lies the swamp. This swamp 

 and the higher places near the shore are covered with grass, on top 

 of which the sea in times of storm has cast old planks, stumps, boxes 

 and all kinds of rubbish. It was under these that the shells were 

 found. There was one exception however. Pyramidula alternata 

 Say, I found under stones. I found them within a foot of where the 

 vegetation ended and the rocks began that went down to the sea. 

 Indeed all the species enumerated below were found within twenty 

 feet of the beach. Sprinkled through the grass are the shells of 

 Buccinum nndatum, Littorina and Mytilus edulis. Some have been 

 washed up, others have been carried by the crows and gulls. It has 

 been suggested that it is owing to the abundance of calcium carbon- 

 ate in the soil due to these decomposing shells that land shells are 

 so very abundant at the edge of the sea. 



Vullonia costata Mull. Agriolimax compestris Binn. 



Pupa muscornm L. Pyramidula alternata Say. 



Cochlicopa lubrica Mull. Pyramidula striatella Anth. 



Vitrea hammonis Strom. Helicodiscus lineatns Say. 



Zonitoides arboreus Say. Succinea obliqua Say. 



Euconulus fulvus Mull. 



Little Duck Island lies about eight miles to the southward of Mt. 

 Desert and is the most isolated that I visited. It is about a half a 

 mile in diameter and is half covered with a dense growth of woods, 

 principally spruce. Half is bare of trees and is covered with coarse 

 grass, granite ledges out-cropping here and there. Between the 

 woods and the field there is an area of trees. It was here under 



