hungerford: aquatic hemiptera. 207 



lat., 4 to 4.6 mm.; long., 1.9 to 2mm.; lat. 4.5 to 4.7 mm. Scutellum — 

 long, (measured from prothoracic groove), 1.3 to 1.4 mm.; lat., 2.3 to 2.7 

 mm.; long., 1.4 to 1.5 mm.; lat., 2.7 to 2.9 mm. Insect — long., 8.2 to 9.3 

 mm.; lat., 5 to 5.5 mm.; long., 9.3 to 9.6 mm.; lat., 5.6 to o.l mm." Kan- 

 sas, North Carolina and South Carolina are localities from which this 

 species has been taken. 



Pelocoris hibnpressus Montd. 1898. 



Mont., Bui. Soc. Sci. Bucarest, VII, p. 285. 



Montandon and Champion both mention this as a variety of the species 

 Pelocoiis femorata, as set forth in the key. Stal says it is from North 

 America. 



Pelocoris femorata, P. B. 



Palisot Beauvoris, Ins. Rec. Afr. Am., p. 237. 

 (The follo-^vin? from Uhler, 1884.) 



"Color more or less greenish tei^taceous. but after death it changes to 

 a pale yellow, or horn brown. It has a black line across the base of the 

 labrum; on the prothorax a dark brown quadrangular spot is seen on 

 the middle next the front margin ; each side of this is a ^^^de triangle 

 composed of scattered dots, flanked by larger and still moi-e remote 

 flecks, and with short, almost black lines in a series across the posterior 

 submargin; while the lateral margins are broadly pale. The scutellum 

 is rough, and almost covered by dark brown marbled lines. The slightly 

 convex wing covers ax'e livid brc^\^^i?h, with two nale dots inwardly next 

 to the base of the membrane, and the base of the flat costal margin is 

 broadly pale testaceous. On the venter is a faint trace of silky hair, the 

 sides of the abdomen are marked with six squarish, black spots, and the 

 legs are ivory white, or yellowish. The anterior tibia? are strongly 

 curved, tinged ^^^th piceous and there is a dot of the same color on the 

 apex of the pairs of posterior tarsi. It measures a little more than one- 

 third of an inch." 



Distribution : "Mississippi, New York, New Jersey, Pennsylvania, 

 Maryland, Florida, Illinois, Wisconsin, Minnesota, Michigan, Tennessee, 

 Louisiana and Carolina." — Van Duzee. 



B. Biology of NAucoRiDiE. 

 General Notes. These flattened oval bugs are found amidst tangled 

 growths of Nitella and other water plants. They seem to abound where 

 there is a good shelter of water plants to which they cling. They swim 

 through the water with an even, rapid gait, and catch their prey, which 

 may consist of insects cast upon the water or any aquatic insects it 

 can capture and overcome. 



Genus AMBRYSUS Stal. 



Habitat. Uhler says that Ambrysus signoreti dwells in the quiet 



waters adjacent to streams and in standing pools, especially such as are 



grassy. Another species is found in ponds in Dakota. No one seems to 



have noted the eggs or other biological matters concerning these insects. 



Genus PELOCORIS Stal. 

 This genus, related to the European Naucoris of literature, has been 

 more frequently studied. The notes on the European forms date back 

 to an early time. De Geer noted their swimming ability and stated that 

 they fly at night ; that they eat all sorts of little aquatic animals. Dufour 

 described the eggs of two species, N. cimicoides and A^. maculata. The 



