REHN AND HEBARD 105 



fourth or so sharply bent inwards, there acute or subdepressed. In 

 group C the distal extremity tapers and is gently arcuate inwards. 

 The plastic A. gracilipes is an exception to the rule in this respect, 

 as in certain others, and very rarely specimens of it occur with the 

 distal section of the cerci much as In group C. The subgenital 

 plate always has the lateral margins more or less converging dis- 

 tad, the distal margin varying in width, often individually in 

 gracilipes, and from truncate to deepty triangular-emarginate, the 

 latter decided in group D, where the lateral arms of the emargin- 

 ation are sigmoid. The lateral processes of the distal extremity 

 of the plate are more or less produced, never very long and occasion- 

 ally only knobs, in gracilipes varying greatly in individuals. The 

 ventral surface of the subgenital plate is distinctly tricarinate in 

 insaroides and phantasma. 



Morphological Notes on Female Geniialia.^The supra-anal plate 

 of the female shows very slight variation, this also being true of the 

 subgenital plate. The ovipositor is more sharply arcuate in 

 insaroides, phantasma, phalamjium and grallator, in fact almost 

 bent in certain of these, while in group C and semialata it is much 

 narrower. The dorsal margin is armed with regular serrations or 

 serrulations distad, the ventral margin with recurved serrulations 

 distad, generally passing into crenulations mesad. The surface 

 of the valves is armed distad with low lamellate teeth, which are 

 arranged in longitudinal rows on the dorsal valves and in trans- 

 verse rows on the ventral valves, of which latter those along the 

 lateral suture are generally the most decided and regular. The 

 cerci are tapering and little differentiated in the species. 



Abdominal Features. — In the great majority of the species the 

 abdomen is marked laterad by longitudinal bars of color, generally 

 contrasted whitish and purplish. The caudal margin of the dorsal 

 abdominal segments is, in certain species, more or less angularly 

 produced at these bars and more rarely in a similar fashion mesad, 

 where a less distinct bar is occasionall}^ present. The surface is gen- 

 erally more or less strumose at these color bars, but in one species 

 (phantasma) the production of the margin is present while the color 

 bars have become obsolete. The margins of the dorsal abdominal 

 segments occasionally (carita, limifera and phantasma) are dis- 

 tinctly crenulate, in phantasma thickened points are present be- 

 tween the crenulations. The most decided abdominal structure 



TRANS. AM. ENT. SOC, XL. 



