HiU.: Penobscot Plants. 201 



the shore. Because of the abriijDtness with which this island 

 rises from the sea, its actual height of 556 feet is so magni- 

 fied that the name of ''mountain", locally applied to it, is 

 almost justified. 



The shores of the outer islands are for the most part rocky 

 and abrupt, in many cases almost perpendicular. Sea cliffs 

 and headlands occur, though never of any great height, wher- 

 ever the shores are exposed to the constant buffeting of the 

 weaves, .as on the south side of Swans Island and Isle au 

 Haut. Beaches are common on Deer Isle and the mainland, 

 where the surface is more level. Mud flats and salt marshes 

 are found in tidal estuaries and other protected situations, 

 especially in the shallower indentations. These marshes, 

 however, are small in extent and comparatively scarce, a con- 

 dition very different from that in more southern regions on 

 the Atlantic coast. 



The water courses of the region are very insignificant. At 

 most they are small streams a few miles in length, and in the 

 valleys usually obstructed by glacial drift. Ponds are fairly 

 abundant and belong to three clearly defined types. The 

 majority owe their existence to glacial activity, and these 

 glacial ponds, with but one exception, can be further classed 

 as morainal, a term used by Xichols^ to distinguish those 

 lakes "associated with accumulated glacial debris of any de- 

 scription." In the Penobscot Bay region such morainal 

 ponds occupy the poorly drained depressions or occur along 

 streams behind obstructions of glacial till. With them are 

 universally associated peat bogs in all stages of development. 



Long Pond on Isle au Haut is the only example of a rock 

 basin or scoop lake, one which lies in a depression scooped 

 out of the bed rock itself by the ice. Unlike the other ponds 



1. Bull. Torr. Bot. Club, 42: 170 (1915). 



