144 BULLETIN UNIVERSITY OP MONTANA 



Daphnia Pond. 



Daphnia pond, so-called on account of the great numbers of Daphnia 

 pulex found in it, is a small pond of some ten to fifteen acres. It is 

 about a mile and a half from the Station, alongside the regular wagon 

 road, and only about a half mile from the lake, but at a little higher alti- 

 tude. This pond is no doubt of glacial origin. In the center the watei' 

 is about twenty feet deep, but for the most part the pond is shallow and 

 overgrown with rank vegetation, offering an excellent harbor for smaller 

 forms of life. No fish have as yet gotten into this water, and conse- 

 quently the invertebrate fauna is not affected by them, and has few, 

 enemies. It is a typical place to study some of the forms of life found 

 therein, living as they do under very favorable conditions. The varied 

 and abundant life in this small pond is in strange and striking contrasli 

 to the limited quantity and paucity of species in the large lake, so short 

 a distance away. 



Being in such close proximity to the laboratory it has received consid- 

 erable attention, and is a favorite resort for those seeking material. In 

 or near Daphnia pond may be found the following specimens: 



SHELLS. 

 Planorbis trivolvis Say; abundant. 

 Sphaerium partumeium Say; abundant. 

 Physa ampullacea Gld.; rather commlon. 



Pyramidula strigosa cooperi W. G. B.; in damp places along banks 

 of Flathead lake. 



ENTOMOSTRACA. 



Daphnia pulex; exceedingly abundant, making the color of the water 

 dirty red. May be taken by the spoonful or pint. 



Diaptomus lintoni Forbes; common, but much less abundant. 



Cyclops pulchellus Koch; not uncommon. 



Gammarus, probably two species, one large, an inch in length, swim- 

 ming among the water lilies, 



ODONATA. 



Aeschna constricta, Say; abundant; exuviae to be had in quantity on 

 the rushes and cattails. The adults are on the wing in large numbers 

 in late July and early August. During the first week in August, 1901, an 

 American bittern, Botaurus lentiginosus Montag., was shot whose 

 stomach was crammed with dragonflies of this species. 



Libellula pulchelia Drury; next in size to the preceding. Emerges 

 before August. 



Libellula quadrimaculata; on the wing as early as July 8 in 1901. 



Lestes unginculata; Hag.; in 1899 this species was emerging in large 

 numbers during the last two weeks in July. In 1901 they were just 

 emerging July 8. 



