234 NATURAL HISTORY OF ARTHROPODS. 



They are generally short, plump insects, occasionally with the tip of the wing-covers 

 contracted and produced, and display great facility in leaping. Many of them have 

 a; rough, bark-like exterior, closely matching the limbs and branches upon which they 

 rest, and which serves to conceal them from the eyes of pursuers. 



Bruchomorpha and JSTaso are notable e.xceptions to the general form in this group, 

 in having the head drawn out into a snout like some of the cureulionid beetles. These 

 are either gray, bronze-colored, or black insects, often with a jellow stripe along the 

 head and thorax. J3. dorsata has the head conical, but compressed to an axe-like 

 edge at tip. The head in JSTaso is much larger, also obliquely deflexed and ending in 

 a bulb-like tip. Many species of these genera have been discovered in the United 

 States. They are all small forms, rarely much more than a line in length, and all of 

 which have thus far been described from the arrested imago with short wing-covers. 

 Tliey are found from Canada to Florida, and from Dakota to southern Texas, being 

 met with in large numbers, chiefly in low meadows and on prairies, where they enjoy 

 the juices of the tender grassy plants. The genus Xaso is sometimes common in 

 simila*- places in Florida, Texas, and Kansas. Hibernation takes place in Brucho- 

 morpha, and such females as survive until the return of warm weather lay their eggs, 

 and the young are developed through the summer, so that by the latter part of this 

 season the fully adult individuals appear in the greatest numbers. 



But the types which better represent this group are to be found in such genera as 

 Is&its^ Tylana, Ilysteropterum, and their near allies. In the former we observe blunt- 

 faced, stout insects, having the head very short, much narrower than the thorax, with the 

 wing-covers a little rounded, inflated before the middle, and slightly narrowed towards 

 the tip. The species are usually dull yellow, gray, or brown; and live upon the 

 branches of low trees and bushes. Tylana is represented in the United States by 

 several medium-sized species. The one best known is the T. cotispersa. It is a 

 moderately broad form, of a dull chestnut-brown color, with a few blackish dots on the 

 middle of the wing-covers, having the veins wide apart, and very few ai^ical areoles. 

 When living the under-side of the body is pale green. Specimens occur singly or in 

 pairs, during September and October, on different species of hickory, selecting in prefer- 

 ence the younger and more tender trees. Thus far it is known from only a few of 

 the States bordering on the Atlantic Ocean. Other species have been found in Arizona, 

 Teimessee, and Pennsylvania ; and the genus is represented in the Mauritius by at least 

 two species. 



Hysteropterum is an allied genus which has the head still more blunt and wide 

 than in the preceding. It belongs chiefly to Europe, where it is represented by at 

 least twenty-five species, mostly of pale colors and small size. Mycterodes differs 

 from the foregoing chiefly in having the head conically prominent, and the vertex 

 scooped out and carinated on the sides. M. nasutus is a pale clay-yellow insect, 

 with olive-tinged wing-covers, and dorsal surface of abdomen black. It measures 

 about one-fourth of an inch in length, and inhabits Austria and the southern parts of 

 Europe. 



Issus has the head blunt, but not so wide as in either Tylana or Hysteropterum, 

 but the vertex is very distinctly separated from the front by the transverse carina, 

 and above which the head is made tabulate by the lateral and posterioj- carinate margins ; 

 the face has also a very distinct, incomplete carina down the middle, and the veins 

 of the wing-covers are closely reticulate behind the middle. Issus coleoptratus is 

 perhaps the most widely distributed species in Europe, where also eleven other species 



