In the outer portion of the shore line, at least,shrubs 
often occupy the most exposed situations. The typioal species 
nre Physooarpus opulifolius (L.) Maxim, (ninebark), Rosa 
acicularis Lindl. var. Bourgeauiana Crepin (wild rose), Salix 
petiolaris Sm., and Cornus stolonifera Michx. f. fred-osier 
dogwood). The seedlings of Populus tremuloides often accompany 
the willows. Along the inner portion of the shore, tree seed¬ 
lings are frequent, the commonest being those of Thuja occi ¬ 
dental is L. Here the usual successions occur, with lichens 
and mosses as pioneers. With a few exceptions, they are well 
above the wash of the winter wavos. The wash of the higher 
water can often be very accurately traced on large isolated 
boulders of conglomerate. This material, on account of its 
differential weathering, supports a richer flora of lichens 
and mosses than the sandstone, and the transition from washed 
to unwashed surface often appears rather abrupt. 
Several species of lichen and moss occur in the severest 
situations. The pioneer crustose lichen appears to be Rhizo - 
oarpon petraeum (Wulf• ) Koerb. This form persists often under 
the lash of the winter waves. Other crustose forms common on 
the rooks further back are Plaoodium aurellium (Hoffm.) Tuck, 
and Lecanora oinera afL.) Sommerf. A few species of moss, 
such as Ceratodon purpureus (L.) Brid., Leptobryum pyriforme 
(L.) Wils. and Funaria hygrometrioa (1. ) Sibth., occur in 
