INVERTEBRATES OF LAKES GENEVA AND MENDOTA. 
477 
August 9, deep-water, 4 j). m. sunlight, net hauled about 20 feet below surface. A good col- 
lection. 
1. Leptodora hyalina. Several. 
2. Daphnia retrocurva, var. A great number. 
3. Daplmella hrachyura. Occasional specimens. 
4. Cyclops, sp. Very few. 
5. Epischura lacustris. Very abundant. 
6. Diaptomus sicilis, var. An occasional example. 
August 9, 10 a. 111 ., sunshine, deep water, calm, net dragged about 90 feet below the surface. A very 
large collection. 
1. Leptodora hyalina. A great number. 
2. Daphnia retrocurva, var., with obtuse apex to helmet. A very large number. 
3. Epischura lacustris. Occasionally seen. 
4. Diaptomus sicilis, var. Not abundant. One female noticed bearing spormatophore. 
August 9, deep water, 4 p. m., 10 feet below surface, sunshine, calm. A good collection. 
1. Leptodora hyalina. A few. 
2. Daphnia retrocurva, var. The main part of the haul. 
3. Epischura lacustris. A few examples. 
4. Diaptomus imperfectus. A few examples. 
August 4, upper end of lake, deep water, 9 p. m., moonlight, at surface. Fiue and large collection. 
1. Daphnia retrocurva, var. Many examxiles. 
2. Daphnella hrachyura. Occasional young. 
3. Epischura lacustris. The principal part of the catch. 
August 7, upper end of lake, deep water, 9 p. m., at surface, stiff breeze. A large collection. 
1. Leptodora hyalina. Occasionally observed. 
2. Daphnia retrocurva, var. The greater part of the collection. Females were bearing eggs and 
young in various stages of development, the germinal disk just forming in some, and others 
nearly ready to leave the brood cavity. The female usually carries but a single egg. These 
Daxihnias were feeding on unicellular Algm, as shown by crushing specimens on a slide. 
3. Daphnella hrachyura. A few young examples. 
4. Epischura lacustris. Many specimens. One male seen with a slender spermatophore partly 
extruded. 
5. Diaptomus sicilis. Occasional specimens. 
A repetition of the foregoing. 
1. Leptodora hyalina. A half-grown example. 
2. Daphnia retrocurva. Only occasionally seen. 
3. Epischura lacustris. This collection consisted almost wholly of this species. Evidently 
breeding here rajiidly, the ovaries containing ova, as many as teu to fifteen in each female, 
and the abdomens of all having the spermatophore attached. Many of the ova had a large, 
central, orange globule, and floated when detached. Most of the males with developed 
spermatophores. 
4. Diaptomus sicilis, var. Several specimens .8 to .9““ long. Males with well developed sperma- 
tophores. 
A single short haul of the towing net in the mud of the bottom, at a depth of 10 fathoms, yielded 
several specimens of Pisidium adamsi{the characteristic deep-water molluskof this lakehan occasional 
Daphnia retrocurva var., several cyprids (including Candona elongata), a few dead branches of Polyzoa 
(apparently Fredricella), and a single Limnodrilus — the common mud-worm of the interior of the lake. 
SHALLOW- WATER COLLECTIONS, 1887. 
Several collections made from the margin of the lake to a depth of 9 or 10 feet gave 
a much more miscellaneous list than those from the open water. 
1 . Corethra. Pupa. 
2. Chironomus. Larvm and pupse, the former occurring in every haul. 
