SHIRAS EXPEDITIONS TO WHITEFISH POINT. 131 



two or more feet long, was seen to move away from here on the approach 

 of the boat. Some small fish were seen here, but they were uncommon. 



Shoal Areas without evident Plants. These have a hard, sandy 

 bottom with very few or no rooted aquatic plants. A strip of region 

 of this type examined lay "along the dam at the west end of Vermilion 

 Lake (Station 28) . Fish were uncommon here as at other places of the 

 type and with many hauls of the seine only a few examples of Leuciscus 

 neogaeus, brook sticklebacks, and Iowa darters were caught. There is 

 an extensive shoal of this type at the north end of Little Lake but almost 

 no fish were -found over it. At Station HI, of Hay Meadow Lake, 

 barren shoal is also prevalent with the usual scarcity of fish. 



Shoals with Stonewort Association. Shallow water a few inches 

 •deep with thick bottom mats of stonewort plants is found in a number of 

 bays near the east end of Vermilion Lake. One of these (Station 53) 

 was given particular attention. This extends some three hundred 

 feet into the marsh and is from about twenty to eighty feet wide. Only 

 very small fish, an inch or so long, including many little brook stickle- 

 backs, were found over this growth. Others caught were red-bellied 

 dace, Leuciscus neogaeus, black-head minnow, and Iowa darter. Cray- 

 fish dwelt in the stonewort masses. In the westward prolongation of 

 Spruce Lake (Station 84) stoneworts covered a very thick muck deposit 

 almost everywhere. Large mats of these plants often became detached 

 ^nd came to the surface and floated as shoAvn in (Plate XXIB.) Only a 

 few very small fish were found here as elsewhere where stoneworts 

 -covered the bottom. 



Shoals with Water Weed Association. Water weeds (Elodea cana- 

 densis) grow in dense patches on a hard sand}" bottom in Hay Meadow 

 Lake (Station 111), where the depth is about two feet. Many Iowa 

 darters were found among these plants, but no other fish were found 

 Avith them. 



Shoals with man}" Aquatic Plants formii^g a dense, complex Associa- 

 tion. In a few, shallow, sheltered places, submerged plants are num- 

 erous, filling the water. One of these is at the west end of a small lake 

 (Station 101) where pondweeds, stoneworts, bladderworts, green algae, 

 with partly submerged rushes, sedges, sweet gale, and other plants form 

 a complex association that nearly fills the water leaving little swimming 

 space for water animals (Plate XXIIIB). The entire lake is char- 

 acterized by an abundance of vegetation (Plate XXIIIA). At Station 

 101 mud minnows are common, and this is a typical habitat of the 

 species. A great many small Leuciscus neogaeus were caught along the 

 margin in different parts of the lake. These were about an inch in 

 length. A few small Iowa darters were also caught in this lake. A 

 small pike was noted. The following aquatic invertebrates were 



