BUGS. 233 



Diptera of the genus Pyrgota. They are all feeble insects, which leap with only 

 moderate facility, and which depend chiefly upon their large wings to escape from 

 enemies. 



A series of this group stands apart from the other genera in being destitute of the 

 appendages commonly attached to the base of the antennae. One of these is the 

 American genus Lamenia^ which is represented in the United States by three species 

 of slate-blue color, more or less powdered with white, and closely resembles the 

 neuropterous genus Aleuronia. The best known of these is distributed from Maine 

 to Georgia, and from Illinois to Texas. It is the L. vulyaris, a broader-winged insect 

 than either of the forms noticed above, in which the forehead is not produced, but 

 vertical, gently curved downwards, and strongly keeled on the side margins. Its eyes 

 are large, and the knob-like antenna? placed immediately beneath them are guarded by 

 a scoop-shaped appendage of the cheeks. Specimens usually occur singly or in pairs 

 upon a great variety of plants and trees. They have been taken from the skunk- 

 cabbage, alder, and wild grape in June and July, and from the oak and hickory in 

 late summer and until near the end of October. When rubbed, or wet by rain, they 

 appear black, blue black, or purplish-black ; but when freshly changed from the nymph, 

 the colors are paler, bluish tinged with white. This species measures about one-sixth 

 of an inch to the tip of the wing-covers ; but there are other species in Arizona and 

 the Atlantic region of much larger size, and tinted with brighter colors. 



The genus Mysidia belongs here, which has species nearly half an inch in length, 

 and which closely resemble various kinds of pale-colored moths. It belongs to the 

 tropics of South. America. 



Another sub-family, the Lophopida, belongs to the Orient and Africa. Thus far 

 none of its representatives have been discovered on the western continent. A single 

 form from Caffraria, Elasmoscdis cimicoides^ will serve to distinguish this small but 

 singular group. In form it is reversed lyrate, with the front of the head narrow, 

 scooped out, and the carinate sides raised like ears. Its wing-covers are rounded at base, 

 diagonally narrowing towards the end, cut obliquely inwards at tip, and having the 

 wide and very conspicuous costal areole crossed by numerous veins. Both its fore- 

 thighs and shanks are expanded into wide, flat plates. Its ground color is a clear light 

 brown, with a window-like whitish spot on the _ middle of the wing-covers, and with 

 various other white spots on the outer margin. It measures about one-third of an inch 

 to the tip of the wing-covers. 



In the next sub-family, the Issida, we meet witli a very large assemblage of close- 

 set, robust forms, widely distributed in both temperate and tropical regions, and rich 

 in genera and species. Already more than fifty genera, including over two hundred 

 species, have been reported from Europe, Africa, the United States, Mexico, and 

 South America. Two genera, Hysteropterum and Tssus, are unusually well provided 

 with species in the first-mentioned country; but North America, the West Indies, 

 and Brazil have a preponderance of the abnormal and singular forms. 



This sub-family is characterized by a wide, generally blunt head, scarcely narrower 

 than the thorax, feebly or not at all carinated on the sides. The base of the prothorax 

 is cut straight off, or only very slightly concave, and the exposed dorsum of the meso- 

 thorax is short. The wing-covers are thick, broad, curving over the body, sometimes 

 nearly enclosing it, and they often have numerous, close-set areoles from near the base 

 to the tip. Their shanks are stout and prismatic, the hind pair often armed with 

 coarse spines on the outer edge, and the tip is crowned with groups of short teeth. 



