416 The University Science Bulletin. 



country are not numerous, and since it is necessary for the traveler, 

 whatever his mission, to seek the places where water may be had, 

 it is probable that a considerable number of the places where water 

 insects might occur were observed. In each of these a collection, 

 representing as far as possible all of the species present, was ob- 

 tained. The collections include mainly those from springs and 

 "tanks." It is possible that water insects could have been found 

 in some of the seepages along streams or in the permanent streams, 

 but there was no opportunity to make special search for these. 



SMALL "tank," one AND ONE-HALF MILES ABOVE MOUTH OF MULEY 

 TWIST CREEK, EASTERN GARFIELD COUNTY, UTAH. 



Muley Twist creek is an intermittent stream whose bed is dry 

 the greater part of the year. It occupies a very deep box canyon, 

 carved in massive red and yellow sandstone. About seventy-five 

 feet above the bottom of the canyon, on its sloping west sandstone 

 wall, was found at one point about one and one-half miles above 

 the mouth of the creek, a little "tank" about one by two feet in 

 width and length and with greatest depth of approximately one 

 foot. The depression was filled with clear water, part probably 

 caught in a recent rain and part derived from a very small seep in 

 the sandstone above. The "tank" is probably not at all permanent. 

 It was surrounded by bare smooth sandstone, without any near-by 

 plant growth. 



In this little basin lived a group of seven individuals of Arcto- 

 corixa abdominalis Say, without other insect life. 



"tank" about two MILES ABOVE MOUTH OF MULEY TWIST cllEEK, 

 EASTERN GARFIELD COUNTY, UTAH. 



On the east side of the Circle Cliffs and along the Water Pocket 

 Fold in eastern Garfield county are a number of "tanks" which con- 

 tain water in all but the driest seasons. From one of these, in the 

 bed of Muley Twist creek, beneath a high sandstone cliff, a number 

 of water bugs were taken. The pool was about eight feet in 

 diameter and three feet deep in one part at the time of our visit in 

 August. Two or three large cottonwoods shade the pool, but there 

 is almost no other vegetation near at hand. 



In this little basin was taken one dytiscid beetle, Rhanhis bino- 

 tatus Harr., and upon the surface eight specimens of Gerris orba 

 Stal, all winged, and one pair mating (five males and three females). 

 The solitary dytiscid beetle appears to be a new record for Utah. 

 Its previous capture has been recorded for Wisconsin and Arizona. 



