260 NATURAL HISTORY OF ARTHROPODS. 



especially where reeds or water-plants remain rooted through the winter. Upon the 

 first approach of mild weather it leaves the winter retreat, moves actively about, and 

 soon prepares to lay the eggs, which it glues to the submerged leaves and sprays of 

 plants. 



This genus is replaced in Europe by Naucoris, of which JV. maculutus is the best- 

 known species. It is a more oblong form than the preceding, of a pale testaceous 

 color, clouded and marked on the head, disc of prothorax, and scutellum with chest- 

 nut brown, and the wing-covers are clouded, dotted, and freckled with darker brown ; 

 the connexivum has a series of brown spots, while the legs and under side are pale yel- 

 lowish. It is of about the same length as our native Pelocoris, but less convex 

 posteriorly. This species is distributed chiefly throughout France, but is also found 

 in various parts of Algeria. 



By far the most widely-distributed while well-known European species is the common 

 Ilyocoris cimicoides. It is described in the manuals of entomology as JVf.mcoris cimi- 

 coides. In this genus the mesosternum is raised into a high carina, the 

 second joint of the rostrum is not covered by the labrum, the anterior 

 femora are expanded downwards at base, and the fore-tarsi are destitute 

 of a conspicuous nail. The insect is about twice as large as the foregoing ; 

 when alive it is of a yellowish green color, highly polished, the head has 

 a pair of stripes on the middle, and the base two blackish parallel spots ; 

 the prothorax is obscured on the disc with dark, confluent spots, and 

 sma ^? scattered flecks, which are absent from the sides, middle line, and 

 the transverse line near the base. The wing-covers are obscured with 

 brown, excepting the wide depressed base of the costal area ; the connexivum is crossed 

 by brown lines at the incisures of the segments ; the sternum and middle of the venter 

 have some obscure, broad areas, and the spines at tip of posterior pairs of tibiae are more 

 or less piceous. It measures rather more than half an inch in length, and is somewhat 

 long-oval in outline. It is pretty generally distributed throughout Europe, being quite 

 common in England, where it inhabits ponds and ditches in which aquatic plants grow 

 freely. Its motions are described as rapid, and it swims well by using the two pairs of 

 hind-legs. The eggs are said to be oblong, nearly cylindrical, curved, whitish, and cut 

 off obliquely at their front end. They are likewise glued to the stems and leaves of 

 plants under the water. Our attention is here arrested by the fact that this genus has 

 several species in the tropics of Brazil, while in North America, where the climate 

 agrees better with that of Europe, not a single representative of it has been found. 



Probably the most beautiful form belonging to this group is the Ambrysus. It has 

 a very distinct pattern of marking, accompanied by an exceptionally 

 round figure, which gives it somewhat of a medallic appearance. Our 

 most elegant species is A. signoretii. It is of a bright clay yellow 

 color, paler beneath, with ivory yellow legs and labrum. The head is 

 deeply seated in the prothorax, is bluntly produced behind, and sinu- 

 ated each side, with broad, lunate, brown eyes, Avhich are more than 

 half enclosed by the wide, flat sides of the pronotum. The vertex 

 is thinly, unevenly spread with brown : there is a brown double streak FIG. 319. Ambry ms 



J ' . . . signoretii. 



down the middle, running into a double spot of the same color at 

 base. On the depressed sides and at base the pronotum is pale, very minutely 

 punctate; while on the disc it is marked with two large triangular, emarginated 

 spots composed of brown dots, and between these two, in front, it is transversely 



