BUGS. 265 



Our largest species is R. quadridentata. Its natural color is pale dull ochreous, 

 with the dorsum of the abdomen reddish and longitudinally marked with smoke brown. 

 The fore-femora have a long tooth beneath, nearly one-third way from the tip, and a 

 notch at the end bounded behind by an angular prominence (described as a tooth by 

 some authors) on each side of the grooved line. A marked feature of this species is 

 noticeable in the length of the respiratory tube, which is as long as the abdomen and 

 basal segment of the prothorax united. The male is somewhat smaller and thinner 

 than the female, and may be recognized by the flatter, less hairy last ventral segment. 

 This species is distributed from Albany, N. Y., to Sonora, Mexico. 



Many other species belong to this genus. The most robust and the largest are 

 those from Japan and China; the latter, M. chinensis, has the upper side of the abdo- 

 men black, with the side margins clay yellow. H. fabricii inhabits Cuba and the 

 other Great Antilles, and is remarkable for having the respiratory tube one-fourth 

 longer than the whole body. M. annuUpes inhabits the tropics of South America from 

 Demerara to Rio, and has the legs banded with fuscous. One species, the Ji. linearis, 

 has the upper part of the abdomen bright red ; it inhabits Europe. About twenty 

 species are already known from the temj^erate and warm parts of the earth, and at 

 present the eastern hemisphere, including Madagascar, Africa and its islands, seems to 

 have the larger number of species. They may be regarded as the aquatic representa- 

 tives of the Emesidse, having habits likewise rapacious and carnivorous. 



We now reach the family Belostomid^, which contains the largest Heteroptera 

 now in existence. These are all wide and flat-bodied aquatic insects, of more or less 

 ovate outline, furnished with powerful flattened swimming-legs, the fore-tibiie curved 

 as in the preceding family, and fitted for seizing and holding tightly the victims (fish 

 and other creatures), upon which they pounce from their hiding places in the rubbish 

 or among the branches of water-plants. Their color is always some shade of brown, 

 generally with some faint marks of fuscous or blackish, especially upon the legs. This 

 group, as at present known, consists of about one dozen genera, distributed over most 

 of the temperate and torrid climates of both hemispheres. 



Here the head is much narrower than the prothorax, although the large triangular 

 eyes sometimes project above and beyond its lateral margins ; the front, including the 

 base of the rosti'um, is more or less long-conical, with the rostrum short and three- 

 jointed. The antennae are short, composed of four joints, and rest concealed beneath 

 the eyes. Behind the wide, trapezoidal prothorax, a lai-ge triangular scutellum suc- 

 ceeds, varying much in length, but never equalling the former in width. Notable 

 differences appear in the form of the metathorax, which in some genera is very narrow, 

 while in others it is wide and extends on either side of the scutellum. The wing-covers 

 are generally well separated into corium and membrane, and the former is usually 

 furnished with numerous irregular meshed veins. A remarkable feature of all the 

 genera is in the presence of a pair of flattened, narrow, strap-like appendages at the 

 end of the body which are extensile, but not concerned with respiration, as in mem- 

 bers of the foregoing group. 



America possesses the largest and most conspicuous members of this group ; while 

 India, China, Japan, and northern Africa each has its characteristic representative. 

 These belong to the genus Jielostoma, and the chief of them all is the £. grandis, 

 which inhabits the sluggish ' waters of Guiana and Brazil. As seen in collections 

 it is a dull yellowish-brown insect, marked with dark brown on the fore-part of 

 the prothorax, and on the disc of the scutellum, which has a tablet-like mark 



