BUGS. 253 



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a victim is seized it is held with unbending tightness until all the fluids of its body are 

 completely withdrawn. These insects resent handling, and if not cautiously picked up, 

 take advantage of tlie first opportunity to plunge their beak deeply into the flesh of their 

 captor, and thereby produce a keenly smarting pain which lasts for several minutes. 



The genus Anisops belongs here, and is composed of much more slender forms 

 than the foregoing, in which the fourth joint of the antennae is longer than the third. 

 The males of some of the species have, in addition, an acutely produced forehead. Our 

 best known North American species is A. platycnemis. It may be known from the 

 others by the unusually widened fore-tibiae of the males. The color is ivory white or 

 pale yellowish, sometimes with the scutellum and base of the dorsal surface of the 

 abdomen bright orange ; the venter, breast, end of abdomen on the dorsal surface, 

 upper sides of the femora, and dorsurn of the thorax beneath the prothoracic outer 

 shell, are more or less black. The wings are milk white, and, together with the wing- 

 covers, much longer than the abdomen. It measures about one-fourth of an inch to 

 the tip of the wing-covers. Thus far it has been met with from Maine to Cuba ; it is 

 also found as far west as Illinois, and from thence to Texas and over the Rio Grande 

 to Tamaulipas, Mexico. In the State of Maryland it seems to prefer cold spring- 

 water, in which I have found it generally late in October, after the frosts had set in. 



The genus Ploa contains the pigmies of this family, none of them much exceeding 

 a line in length. Only one species, P. striola, has thus far been found in the United 

 States. It is a much deeper-bodied form than either of the preceding, lacks the mem- 

 brane of the end of the corium, has the ends of the wing-covers high and cut obliquely, 

 the eyes brown, and with a reddish-brown streak on the middle of the front, and some- 

 times a dusky spot near the tip of the corium. It has been found in Massachusetts 

 Illinois, Kansas, and Texas. The genus is interesting from having a minute supple- 

 mentary joint attached to the side near the tip of the long and stout third joint of the 

 antennae. It is a highly polished, coarsely punctate species, with a wide, bluntly 

 curved head, and short legs. 



Another family of truly aquatic insects is the NEPID^E. It is composed of flat, 

 elliptical or elongated, fuscous or pale brownish species, with legs fitted for walking 

 rather than for swimming, and with the fore-tibiae curved, and carrying a long, one- 

 jointed slightly bent tarsus. These two last, united, fit into a channel of the long and 

 wide femora, like the blade of a pocket-knife. The head is narrow, and surmounted on 

 each side by a prominant oval eye; the membrane is well distinguished from the 

 corium, and the abdomen is terminated by two long, respiratory 

 half-tubes, which, applied together, serve as a pipe to convey the air 

 to the interior of the abdomen. 



Our native species, Nepa apiculata, is of a dull fuscous gray color, 

 with the base of the abdomen above more or less tinged with reddish. 

 It is of an elliptical form, blunt in front, with a ridged middle line 

 on the vertex, and with three short raised lines on the prothorax, 

 each side of a longer one on the middle. The surface and mar- 

 gins of the thorax and head are roughly granulated, while these, to- 

 gether with the scutellum and corium, are rough and closely covered 

 with stiff, short pile. The anterior femora have no tooth on the IG apicuiata? pa 

 inner angle, but instead there is a prominent elbow, forming a 

 wide expansion for the sides of the deep gutter. The wings are smoke brown, 

 with darker veins. This species closely resembles the European one, and meas- 



