60 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
TOPOGRAPHY. 
The conditions in that portion of Lake Erie around Put-in Bay and Sandusky 
differ from those at St. Clair and at Traverse Bay. While the bottom and shore 
formations are not as abundant as in Lake St. Clair they are very much more 
abundant than at Charlevoix. The region about Put-in Bay and Sandusky is of 
limestone formation, Put-in Bay, or South Bass Island, East and West Harbor, 
belonging to the waterlime group, while about the mouth of the Portage River there 
is an outcrop of Salina shale. The channels between the islands have been scooped 
out of the limestone rock by glacial action, and the bottom is either of this rock or 
is covered with drift clay. 1 Much of the coast on the mainland is rocky and pre- 
cipitous, but a great part of it is sandy beach (pi. 11, fig 6), especially at East and 
West Harbors and at Port Clinton, while at Catawba Island and at Marblehead light 
the limestone rock juts out into the lake, breaking the continuity of the sand beach. 
The islands, of which there are on the American side six larger and as many smaller, 
usually present rocky shore lines to the waves (pi. 11, fig. -1), but there is one sand 
beach on South Bass Island and portions of the bay are less rocky than the west 
shore. The water is generally of considerable depth close to the rocks, and the 
bottom is covered with stone and gravel overlying a blue clay that comes to the 
surface in the deeper parts. In Put-in Bay the bottom is generally muddy close up 
to the shore, and in the western end, at Squaw Harbor, and also near the United 
States fish-hatchery, the bottom slopes gently, thus furnishing the conditions favor- 
able to the growth of water plants. These parts of the harbor are, too, the most 
protected from the violence of the waves. 
At four points on the mainland between Sandusky and Port Clinton there are 
extensive swamps, about upper Sandusky Bay, at East and at West Harbors, and 
along the Portage River at Port Clinton. These swamps are characterized by a great 
extent of low-lying muddy bottom, covered with varying depths of water and sloping 
back to low wet ground (pi. 11, fig. 1). They are intersected by many channels, 
some opening out to the lake or river, while others lose themselves in the body of the 
marsh. Pools of greater or less extent frequently occur. At Port Clinton and at 
Sandusky the swamps border the rivers and extend for miles up the stream, while at 
East and West Harbors they open directly into the lake by narrow channels, which 
are protected from wave action by sandbars. 
DISTRIBUTION OF AQUATICS. 
Phanerogamic water plants form a class distinguished from land plants by many 
differences of structure and form due to their peculiar habitat. The variety of form 
and the high development of land plants is wanting in aquatics, because a few types 
and relatively simple structure suffice to meet the nearly uniform conditions of their 
existence. Their distribution is almost world-wide, many of the species being found 
throughout the temperate zone and some even from the Arctic Ocean to the Equator. 
They grow in streams, pools, and lakes, in flowing and in still water; some species 
even flourish in stagnant water; and, together with marsh plants, they form the bulk 
of the vegetable matter m lakes and streams. 
1 Ohio Geological Survey, vol. n. 
