BUGS. 259 



A single step in advance leads to the Naucorid^. Here, as in the preceding 

 group, we notice flat-bodied, mostly oval insects, of smaller size, destitute of ocelli, 

 having raptorial fore-legs ; and with hind limbs fitted for crawling rather than for 

 swimming, having tarsi of two joints, armed at tip with two sharp claws. The 

 antenniB are composed of four simple joints, well concealed beneath the eyes ; and 

 the rostrum is short, three-jointed, acute, but covered at base with a large, transverse, 

 plate-like labrum. These all lack the caudal setse ; and have the last segment of the 

 abdomen well differentiated, so as to distinctly mark the sexes. They are fond of 

 reedy and gi-assy quiet waters, where they creep about like the dyticid beetles, creep- 

 ing and half-swimming around and between the leaves and sprays of the submerged 

 plants, and suddenly seizing any unlucky Corisa or other insect that happens to be 

 within reach. The fauna of the southwestern United States is rich in the species of 

 this group, and shares with Mexico and Lower California some of the most curious 

 and beautiful of its species. 



The most widely spread North American species thus far discovered is Pelocoris 

 femorata. It has been distributed into the collections of Europe and the United 

 States with the name Naucoris poeyi. It inhabits the whole eastern side of North 

 America, from Lower Canada to Florida, and from thence to Cuba and other West 

 India islajids. This genus is closely related to Naucoris proper, from which it differs 

 in the eyes being shorter, lunate, instead of tapering as they converge toward the 

 front. The prothorax is transverse, more convex across the width than in length, 

 curving in continuity with the head ; and the head is seated into it up to the middle 

 of the eyes. A curious feature is noticeable here in . the anterior femora, which are 

 broadly rounded at base, unevenly cordate, and attached to the coxse at a point con- 

 siderably removed from the basal end. The presternum is raised into the form of a 

 pyi-amid, and the mesosternum is distinctly carinated. When alive this species is 

 more or less greenish testaceous, 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 mai-gin; each side 

 of this is a wide triangle, composed of scattered dots, flanked by larger and still more 

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

 sub-margin ; while the lateral margins are broadly pale. The scutellum is rough and 

 almost covered by dark brown marbled lines. The slightly convex wing-covers are 

 livid brownish, with two pale 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 tibise are strongly 

 curved, tinged with 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 in length ; 

 and is often made to appear darker than its actual color by the carbonaceous matter 

 which attaches to its outer surface when pushing its way among the rubbish at the bottom 

 of ponds. It has an exceedingly acute rostrum, and uses it with great freedom upon 

 small molluscs, larvae of dragon-flies, and other creatures which live in its vicinity. 

 The unwary collector who handles incautiously the insects taken from the water with 

 the dip-net sometimes finds a sudden sharp pain in his finger, caused by the puncture 

 of one of these irascible little fellows, who is ever on the alei-t to inflict punishment 

 upon those who withdraw him from his place of abode. This species hibernates at 

 the bottom of pools and ponds, in places where it can find some depth of muck, and 



