174 



THOMAS SAY 10CXDATIOX 



letter M ; lateral tubercles more or less oval in outline ; the 

 three ocelli forming an almost equilateral triangle; hind 

 ocelli larger than the anterior ocellus and closer to each 

 other than to the eyes; antennae brown, lighter at base. 

 Prothorax wider than 

 long, the angles sharp 

 or narrowly rounded ; 

 surface not strongly 

 rugose ; the rugosities 

 in the form of longitudi- 

 nally outcurvecl, more 

 or less broken, lines, 

 leaving a median longi- 

 tudinal smooth field 

 which is narrowest in 

 the middle. Legs yel- 

 lowish; femora usually 

 with a broad, dark 

 transverse band just be- 

 fore the distal end. 

 Wings uniformly hya- 

 line or subhyaline. Ab- 

 domen brown ; cerci or 

 tails about as long as 

 abdomen, the basal seg- 

 ments (except the first) 

 much wider than long 

 and more or less dis- 

 tinctly separated, grad- 

 ually tapering toward 

 the tip and rather 

 thickly covered with 

 short hairs. 



Male. Ninth abdominal sternite produced beneath so 

 as to cover segment 10 completely, and bearing a 

 rounded or squarish raised tubercle or hammer. The 

 tenth abdominal segment almost completely withdrawn 

 into segment 9. The subanal lobes are produced dorsally 

 into short recurved hamules which recurve over the ab- 

 domen and reach onto the dorsal surface of the tenth ter- 

 gite. The ninth, tenth and sometimes eighth tergites 

 usually bear numerous short spines. 



Female. The hind margin of the eighth sternite 

 either unmodified or produced into a distinct subgenital 

 plate. 



Fig. 24. Acroneuria abnormis Newm. 



