42 ILLINOIS BIOLOGICAL MONOGRAPHS [274 



setae representing the paralateral group. The ninth tergum is shield- 

 shaped, longer than wide, the caudal margin concave and provided with 

 numerous setae, while the cephalic margin bears only a few chalazae. 

 The tenth tergum is visible from the dorsal aspect as a small, brown 

 colored, chitinized area caudad of the ninth tergum and is provided with 

 a single chalaza on each side of the meson. Each of these chalaza is sur- 

 rounded by a group of small setae. The ninth sternum is about one-half 

 as long as its tergum, deeply emarginate on its caudal margin, and bears 

 two chalazae on each side of the meson, each of which is surrounded by a 

 few setae. The tenth sternum is longer than its tergum and bears a dark 

 colored spot near the lateral margin. The legs are slender, well developed, 

 and longer than the body is wide. 



Microweiseini 



The body is small, elongate, fusiform, depressed, widest at the meta- 

 thorax, provided with setae, and light-brown to yellowish-tan colored. 

 The head is dark-brown to black in color and chitinized. The mouth is 

 directed cephalo-ventrad and the mandibles are unidentate. The epi- 

 cranial arms diverge slowly from the occipital foramen and become obsolete 

 near the antacoriae. The spear-shaped front and post-clypeus are divided 

 on the meson by a distinct, dark colored, chitinized bar which extends from 

 the occipital foramen to the clypeo-labral suture. The prothorax is oval 

 and slightly wider than long; while the mesothorax and metathorax are 

 distinctly wider than long. The terga of the thoracic segments are longi- 

 tudinally crossed by a small dark-colored area on each side of the meson, 

 more distinct on the prothorax than on the mesothorax or metathorax. 

 The ninth abdominal segment is conical, narrower than the eighth, and 

 about twice as long as wide. The legs are well developed and extend 

 beyond the sides of the body; the tibiae are provided with two paddle- 

 shaped tenent hairs at the distal end; the tarsal claw bears a distinct appen- 

 diculate tooth; and the coxacoriae are distant. 



Microweisea Cockerell 



This genus is represented in the material studied by a single species. 



Microweisea misella Le Conte. — The body is fusiform, elongate and 

 light-brown to yellowish-tan in color. The head is elongate, dark colored, 

 and chitinized. The epicranial arms are present, but the epicranial stem 

 is wanting. There is a dark-brown heavily chitinized bar extending along 

 the dorso-meson from the occipital foramen to near the clypeo-labral 

 suture. The mouth is directed cephalad. The prothorax is wider than 

 long and somewhat oval in outline. There are two brown chitinized spots 

 near the middle of the dorsum adjacent to the meson. The dorsum is 

 provided with a very few short setae. The mesothorax and metathorax 



