HUNGERFORD: AQUATIC HEMIPTERA. 53 



time, unable to settle the point. O. banksi can readily be separated from 

 americamis by its difference in color, markings, and the character of the 

 pronotum. Apex of membrane is more narrow than in americanus." 



O. americanus Uhl. 1876. 



Bui. U. S. Geol. Geog. Surv. 1, p. 335. 



"Broadly oval, slaty-blackish, opaque, the pronotum a little narrower 

 than the abdomen. Head polished, minutely punctured in part, invested 

 with very sparse prostrate pubescence, which is more dense beneath; 

 rostrum reaching the end of the second ventral segment, blackish-piceous 

 on the swelled base, the rem.ainder pale ruf o-testaceous ; antennae pale 

 piceous; face obsoletely carinate, each side with a series of oblique 

 wrinkles, its anterior and lateral boundaries carinated. Pronotum trans- 

 verse, velvety blackish, with a few short wavy lines and some dots of 

 bluish lead-color, and remotely golden pubescent; the lateral margins 

 slightly oblique, only a little narrowing anteriorly, and rounding against 

 the anterior angles, which are distinct and almost acute; touching the 

 margin a little way back, each side, is a small triangular yellow spot; 

 posterior angles subrectangular; the posterior margin waved each side 

 of the center, where it is also a little yellowish. Pectoral surface dull 

 black, with very sparse sericeous scales exteriorly; the spots of the dorsal 

 margin equally visible beneath; sternal margins piceous. Legs dull pale 

 piceous-yellow. Hemelytra broad, widening posteriorly, velvety black, 

 pubescent, sprinkled with golden pubescence, spotted and dotted with 

 bluish lead-color; the costal margin yellow, and with five small yellow 

 spots; membrane bluish lead-color, with the nervures black. Venter 

 piceous black, densely, minutely sericeous pubescent, the edges of the 

 segments and the tip of the last one a little reddish-piceous. The con- 

 nexivum is unspotted, and the surface of the tergum black, polished, with 

 rufo-piceous edges to the segments. 



"Length, 5 millimeters. Width of pronotum, 2i/2 millimeters. Width 

 across the hemelytra, scantily 3 millimeters." 



Has been found in Nebraska, Illinois, Texas, Arizona, Massachusetts, 

 New York, New Jersey, Pennsylvania, Maryland, North Carolina and 

 Florida. 



B. Biology of the Ochterid^. 



General Notes. These bugs are spritely fellows, dark in color, that 

 live upon the shores. They are predatory in habit. 



Habitat. Uhler says of O. aTnericanus : "This is a gay, active little 

 insect, which measures only one-fourth of an inch in length, and lives 

 among the grass and weeds on the margins of brooks and ponds from 

 Massachusetts to Texas. 



Hibernation. Dufour said that these insects appear in April. Thus 

 they overwinter as adults. Practically nothing is known of their life 

 history. Dufour describes the nymph of a species. But concerning the 

 egg, number and length of the instars, etc, we have no data. 



Feeding Habits. Uhler says that the fore legs of O. americanus "are 

 slender and fitted for running, not calculated for seizing and holding prey, 

 as in Galgulus and Mononyx. The rostrum is, however, a dreadful instru- 

 ment, sharp as the finest needle, extremely thick and stout at the base, 

 and a deadly probe to a poor larva of horse-fly or other insect which lives 

 next to the surface of the ground in situations near water." 



