418 The University Science Bulletin. 



Muley Twist creek. The adjacent rocks, chiefly sandstone, are 

 nearly bare of vegetation, though not far distant are numerous 

 pinon, scrub cedar and sagebrush. The spring varies somewhat in 

 volume, but does not commonly dry up in the spring dry season. 



On the surface of the spring and the little stream below are 

 numerous representatives of the species Trepobates pictus and Gerris 

 remigis. A large number of individuals of each were obtained, in- 

 cluding a considerable number of nymphs belonging to the first 

 species. The Trepohates were more numerous than the Gerrids at 

 the time of obser^'ation in August, 1921 — a rather unusual condition 

 as compared with other localities inhabited by the two forms. 



SPRING on upper HENRIEVILLE CREEK, SOUTH CENTRAL GARFIELD 



COUNTY, UTAH. 



An area of special scenic and geologic interest in southern Utah 

 is Table Cliff and the surrounding very rough district in south 

 central Garfield county. South of Table Cliff, on one of the branches 

 of upper Henrieville creek, is a seepage of very alkaline water, the 

 only source available for camp use in the head canyons under the 

 cliff. The water is so strongly mineralized as to be hardly potable. 



On the surface of the short, trickling stream below the seep several 

 water bugs were taken. A few Gerris remigis Say and a considerable 

 number of Micro velia are the inhabitants of this apparently in- 

 hospitable haven. The Microvelia species of this region has not 

 been determined. It may be new. 



"tank" NEAR SOUTH POINT OF KAIPAROWITS PLATEAU, EASTERN 



KANE COUNTY, UTAH. 



Most of the observed watering places in southeastern Utah did not 

 contain water insects at the time of visit in the summer of 1922. Of 

 four springs and pools on the top of Kaiparowits plateau, a high 

 tableland which extends southeastward toward Colorado river from 

 the uplands farther north, only one appeared to contain any 

 aquatics. This was a partially rain-filled "tank" in the bottom of 

 one of the narrow, steep-sided canyons which cut the plateau sur- 

 face. The "tank" was carved in bare, massive sandstone, without 

 near-by vegetation. The pool was about six feet long by one foot 

 wide, and its maximum depth a little over one foot. In this pool 

 were several Notonecta insulata Kirby, but no other water bugs. 



