AQUATIC INVERTEBRATE FAUNA OF WYOMING AND MONTANA. 233 



i 

 Woody beaver pool near Soda Butte Creek, September 1, 1891 : 



Agabus sp. (two). 

 Hydroporus sp. (several). 

 Colymbetes sp. (one). 

 Dytiscidne (larvae). 

 . Corisa sp. (several). 

 Ephemerid larvae (a few). 



Chironoraus larvne (many). 



Phryganeida- (many, with cylindrical tubes made 



of cylindrical pieces of vegetation). 

 Turbellaria (brown cylindrical species. See page 



229). 



Weedy poud near Soda Butte Creek, September 1, 1891: 



Chironormis larva; (a few). 

 Corethra larva (one). 

 Ephemerid larvso (several). 

 Cyclops sp. (one). 



Simocephalus vetulus (very many). 

 Ceriodaphnia sp. (very many). 

 Daplmia pulex (many). 

 Annelida (one, fragment). 



Standing pools left by Soda Butte Creek ; covered with algae ; muddy bottom ; Sept. 1, 1891 : 

 Hydroporus sp. (one). , Cyclops sp. (one). 



Chironomus larvae (a few). 

 Ephemerid larva; (many). 

 PhryganeidiB (small, one). 

 Podurid (great quantity on algie). 

 Gammarus (one). 



Daphnia schncdleri (many). 

 Simocephalus vetulus (very abundant). 

 Ceriodaphnia reticulata (many). 

 Physa sp. (large, two). 

 Chaatogaster p. (one). 



Two circular ponds, each ap])roximately 500 feet across, situated about a mile 

 from Barpnette's Bridge and beside Lainar River, were examined in passing, so far as 

 could be done by alongshore work and by wading out with a surface net. In one 

 there was an abundance of vegetation rushes and a variety of other water weeds 

 and no appearance of alkaline deposit, the bottom being a film of mud on gravel. In 

 the other there were no rushes, but the water was sufficiently alkaline to have a smooth 

 feeling, and the dead water weeds were whitened as they lay upon the bank. 



In the flrst pond, there was a great quantity of dead shells of a large PlanorMts, 

 and fewer of a large Limncea around the margin. Vast numbers of Allorchestes dent at a 

 occurred on the vegetation, and especially in the soft mud of this pond. The ento 

 mostraca were nearly all Copepoda, of the genus IHnptomm, most of them T>. lintoni. 

 Not a single Cyclops was noticed, nor a single Daphnin. A few Ceriodaphnia; occurred, 

 several specimens of Simocephalus vetulus, a very few of Chyditnut spluerictut, and, for 

 the rest, a considerable number of hydrachnids, a few Chironomus larva;, and several 

 larvse of dragon-flies (Agrion). With the foregoing were the common large Corisa 

 of this region, Notonecta, Physa, Deronectes, and a small hydrophylid larva. 



In the alkaline pond near by were a very few mollusks and a moderate number of 

 insects, the latter consisting chiefly of agrionine larvse and small larvie of Chironomns. 

 The entomostraca were much as before, except that Diaptiimus shoshone in small 

 numbers mingled with D. lintoni. 



