100 
Narrow-leaved Cat-tail (Typha an- 
gustifolia) . 
College of Forestry 
Greater Duckweed (Spirodela poly- 
rhiza). 
Mollusks are more or less abundant, the chief location 
being on the dead leaves of the cat-tail. 
Ancylus fuscus, common. 
Planorbis trivolvis, common. 
Planorbis parvus, common. 
VIII. 
Submerged Vegetation Type. 
Planorbis exacuous. common. 
Lymnea stagnalis lilliane, rare. 
(Figs. 29, 30.) 
Stations XXXV, XXXVII, XX XIX, XL. In this type 
of habitat the water is from 4 to 8 feet in depth and the 
bottom is sandy. 
It is usually some distance from the 
shore, either in the outlet or in the lake some distance from 
land. 
submerged vegetation is 
sig Bay is the largest habitat of this kind, but the 
outlet produced the greater number of forms of life. 
The 
very thick, numbering several 
species and affording food and lodgment for a multitude of 
mollusks and other forms of life. The clams and a few 
gastropods live on the bottom, but the majority of gastropods 
(snails) live on the leaves of the plants. Six species of plants 
were noted. 
Clasping-leaved Pond-weed (Pota- 
mogeton perfoliatus) . 
Water Celery (Vallisneria 
ralis). 
Water Weed (Hlodea canadensis). 
Spi- 
Hornwort (Ceratophyllum demer- 
sum). 
Water Milfoil (Myriophyllum spi- 
catum) . 
Stonewort (Chara species). 
Animal life is usually very abundant in this type of habitat. 
MOLLUSCA. 
Blliptio complanatus, common. 
Lampsilis radiata, common. 
Vivipara contectoides, common. 
Campeloma integrum, rare. 
Valvata bicarinata normalis, com- 
mon. 
Bythima tentaculata, abundant. 
Amnicola lustrica, common. 
Galba catascopium, rare. 
Planorbis campanulatus, common. 
Planorbis hirsutus, rare. 
Planorbis parvus, not common. 
Physa ancillaria warreniana, com- 
con. 
Ancylus parallelus, common. 
HIRUDINEA. 
Leech (Glossiphonia picta) . 
