OF WASHINGTON, VOLUME XVI, 10H ]ti."i 



plies two little fountains and irrigates a tiny garden. The creek 

 is here lined with willow bushes, grass and other green vegetation. 

 Beyond this place the creek disappears in the thirsty sand of the 

 canyon. 



The following aquatic or semi-aquatic insects were found by 

 Mr. H. S. Barber and myself in or near this creek during a short 

 visit at the end of June 1901, but a large part of our collection, 

 including the entire alcoholic material was lost in the conflagra- 

 tion which destroyed the city of Williams, Arizona, on July 2, 

 1901. In December 1913 we again visited the place but either on 

 account of the cold weather or on account of the various "im- 

 provements" in the bed of the creek, insect life was much scantier 

 than in the summer of 1901. 



In the upper basin and at the head of the spring the following 

 species occurred: 



Helochares normatus. 



Hydroscapha natans. 



A water mite (Hydrachnid). 

 In or along the middle course of the creek: 



Bidessus subtilis. 



Laccophilus pictus. 



Helophorus obscurus. 



Epimetopus nov. spec. 



Helochares normatus. 



ChcEtarthria minor. 



Creniphilus subcupreus. 



Berosus sp. 



Hydroscapha natans. 



Larva of a Cyphonid (Scirtesf) 



Simulium sp. (larvae and pupae) 



Two species of minute aquatic Dipterous larva? (Chiro- 



nomidse) . 



On the muddy banks of the creek occurred also quite a fauna 

 of riparian Coleoptera of the genera Schizogenius, Bembidim,/, 

 Tachys, Tanygnathus, Actobius, Stenus, Sunius, Medon, Apocellus, 

 and various Aleocharince. On the tall reeds a species of Aphidi- 

 da3 occurred which was fed upon by Scymnus flebilis and its varie- 

 ties. 



In the lower part of the creek the same aquatic Coleoptera 

 were found with the exception of the Epimetopus but there was a 

 species of Dryops and additional riparian species. 



An opportunity to compare the hot water fauna with that of 

 cold water in the same region presented itself in what is called 

 the "Four Tanks" which are merely enormous "potholes" or 

 round waterworn basins cut in the rock by the drainage of a small 

 valley descending the abrupt wall of the canyon through a narrow 



