450 
being about five feet in width and from knee to waist deep. _ In cer- 
tain spots, as at the bridge over which the Glencoe road passes, it 
widens to form a pool twenty feet in diameter and from six to eight 
feet in depth. The ditches are about five feet wide and two or three 
feet deep. In two places (1*) the ditches form wide pools ten or 
fifteen feet in diameter and six to ten feet in depth. 
The characteristic plant life is as follows: 
Chara sp. In the deep pool. 
Polygonum muhlenbergu. In the ditches in a few inches of water. 
Sagittaria latifolia. In shallow water. 
Iris versicolor. In shallow water. 
Sparganium eurycarpum. In shallow water. 
Typha latifolia. On edge of pool. 
Salix longifolia. A heavy clump bordering the deep pool, north 
of the Glencoe road. 
The animal life observed was as follows. 
Mo.Luusks (FLUVIATILE SPECIES). 
Musculium partumeium. 
Physa gyrina. 
Planorbis trivolvts. 
Segmentina armigera. 
Lymnea reflexa. 
INSECTS. 
Limnotrechus marginatus. Water-strider. 
Corixa interrupta. Water-boatman. 
Notonecta undulata. Back-swimmer. 
Hydroporus undulatus. Diving beetle. 
Dytiscus larva. Larva of diving beetle. 
Culex sp. Mosquito. 
Libellula basalts. Dragonfly (adult). 
Anax junius. Dragonfly (nymph). 
Zatha fluminea. Water-bug. 
LOWER VERTEBRATES. 
Ameturus melas. Black Bullhead. 
Esox lucus. Pickere]. 
Rana pipiens, Leopard-frog. 
Natrix graham. Water-snake. 
STATION II. 
(Plates VII. and VIII.) 
The open marsh. It isabout a mile in width. In the spring the 
whole surface is covered with water which is from a few inches to 
