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was very abundant. As the water subsided the masses were often exposed, and were left in numbers to decompose in the air. One of the largest masses seen measured 16.50 inches in greater diameter by 12.50 inches in lesser diameter, with an average depth of about six inches. Small spindle-shaped colonies were common on the stems of dead weeds along the margins of the lakes. The shape of the colony seems to depend entirely on the character of the object upon which it is established. I could not see that fishes, or indeed anything else, fed upon the gelatinous material. Reproduction both by statoblasts and by eggs was in progress in August.


Hydra fusca, Trembley.

These small animals are the closest allies of the corals and sea anemones of salt water, which our streams and lakes furnish. They are, when extended, about 25 inch long, and consist of a tubular body with a circle of tentacles about the one opening, the mouth. They are commonly found attached by the end opposite the mouth to plants and other submerged objects. I was surprised to find them on one occasion in Wood Slough in considerable numbers, and took others with the surface net in the bay, where they must have been floating at the surface. Those taken in Wood Slough, Aug. 4, were multiplying very rapidly by bud-ling. The food consists of small animals which are captured by the tentacles.


These are the lowest and simplest of animals. They are unicellular, and chiefly microscopic. Notwithstanding their minuteness,

, they are of considerable importance as fish food, and are probably still more useful indirectly, since they constitute a large share of the food of insects.

At Quincy the animals of this group varied with the vegetation in the water. Where the plants were common, a variety of species and an abundance of individuals might be expected. In the river they were very rare.

In the deeper water of the bay they were not as common as at its edges, among the wood rafts and the barges. They were most common in the stagnant water of the lakes. Such genera

as Amoeba, Difflugia, Centropyxis, Actinosphærium, Voticella, and Euglena were abundantly represented. In Lily Lake a species of Pyxicola attracted attention from its abundance. It was noticed in the alimentary canal of the singular Dero mentioned above.

Two protozoans are especially deserving af mention here. The elongated green Euglena viridis was always to be found in water dipped up at any place in the bay. When the wind blew toward the west shore for a number of hours together a dense coherent green scum was observed to collect in the inlets and mouths of sloughs, and under the microscope this was found to consist largely of the contracted, spherical Euglene. When placed under the cover glass of the slide they soon become active again. Fishes and other animals could, and probably do, at such times collect them in quantities for food. The second protozoan is Arcella (liscoides which occurred in numbers with the Euglenæ.








DECEMBER 1, 1888.

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