1914] 
Jackson: Land Vertebrates of Ridgeway Bog 
19 
zihethica is more plentiful here than elsewhere; Bufo aniericanus, 
Melospiza georgiana, Mustela v. letifera, Sorex personatus, and 
Blarina brevicauda are found regularly. 
3. The Cassandra Association. The Cassandra Association 
(fig. 3) is characterized by shrubs such as Ledum groenlandicum, 
Chamaedaphne calyctdata, Kalmia glauca, and Alnus mca'ua. 
Sphagnum grows everywhere in dense spongy masses often a foot 
or more deep, and forms a damp layer about the roots of the 
Fig. 3. A Typical Section of the (L\ssandra Association Area in the 
Foreground; the Tamarack-Spruce Area in the Background. 
shrubs among which are numerous open spaces and chambers, 
sometimes containing covered waterholes. Several plants of the 
Sedge Association still retain a foothold here, and Bteiroimna 
quadrifloriim, Spiraea salicifolia, Sarracenia purpurea^ and Poten- 
tilla palustris reach their center of abundance; Oxycoccus oxycoccus 
is common creeping over the surface of the sphagnum. Larix 
laricina encroaches from the Tamarack-Spruce Association. 
