20 University of Michigan 



*Pentacora signoreti (Guerin). — Common on the mud flats 

 about Spring Lake, where the soft muck is encrusted with 

 alkali salts. 



*Saldula interstitialis (Say). — A good series was collected 

 on the muddy margin of a pasture pond at Devils Lake, July 

 20. Other specimens were taken at Devils Lake (at light), 

 at Odessa Narrows, and on the shore of Lake Upsilon in the 

 Turtle Mountains. Uhler (1877, p. 444) records this species 

 from "Dakota." 



NoTONECTIDAE 



*Notonecta undulata Say. — This species was taken at 

 Odessa Narrows on Devils Lake, at Lake Upsilon in the Tur- 

 tle Mountains, and at Stump Lake. The specimen from Stump 

 Lake lacks head and prothorax, but is readily identified by 

 the form of the gonapophyses. 



Belostomatidae 



'*Letliocenis americanus (Leidy). — ^Crystal Thompson took 

 an adult, a nymph, and an egg-mass of this species in Fort 

 Totten Lake during July, 1919. Mr. A. H. Eastgate kindly 

 gave Hubbell two other adults, which were collected under 

 street-lights in Fargo by H. A. Shaw in August, 1892. 



*Belostoma Humineum Say. — Hubbell took two adults from 

 the Bois de Sioux River near Fargo, September 2. One of 

 these individuals was seen to fly over the river and to drop 

 into shallow water near the shore. 



