EEHN AND HEBARD 101 



ranged in regular series. Limbs elongate, slender, terete, cephalic 

 and median femora disto-dorsad with or without an angular and 

 subspiniform production, ventro-cephaHc margins of same unarmed; 

 genicular lobes of cephalic and median femora bispinose, of caudal 

 femora unispinose. Tympanum of cephalic tibiae open on both 

 faces. 



Classification. — From a systematic standpoint the characters of 

 greatest value in the differentiation of the species of the genus are : 

 in both sexes, general form of the body, character of the margins 

 of the dorsal abdominal segments, shape of the eye and the char- 

 acter of the disto-dorsal margin of the femora; in the male, form 

 of the pronotum, form and proportions of the stridulating field of 

 the tegmina, the character of the development of the apex of the 

 stridulating vein, the shape of the speculum and form of the supra- 

 anal plate, subgenital plate and cerci ; in the female, form of the pro- 

 notum, form and relative length of the tegmina and the form of the 

 ovipositor. The general form shows a moderate amount of specific 

 variation in robustness and that chiefly in the female sex, the 

 brachypterous forms and those with reduced tegmina and wings 

 being the more robust, much more so than the males of the same 

 species. The form of the eye is of considerable importance as a 

 diagnostic character, several species (phalangium and grallator) 

 having very elongate elliptical eyes, over twice as deep as wide, 

 while in the other species the form though ovate, elliptical or ovoid 

 is never so narrow proportionately. The form of the pronotum is 

 in general subject to considerable variation, due to differences in 

 the amount of sellation of the whole, the width of the disk, the 

 caudal margin of the same and the degree of bullation of the lateral 

 lobes. The general form of the pronotum is very distinctive in 

 one species (phaniasnia), not being even approached by the other 

 forms, the texture and coloration of the same section being equally 

 characteristic. The degree of bullation of the lateral lobes needs 

 careful attention when used as a character in this genus, as fre- 

 quently specimens which have in nature a considerable bullation 

 of these lobes will show little in the dried condition. This appears 

 to be due to compression in pinning the specimen or shrinkage in 

 the drying process. As a rule, aside from such relatively evident 

 cases, the amount of this bullation is constant and specific, but in 

 A. gracilipes it is much less stable and as uncertain there as a num- 

 ber of other features in that plastic species. The relative length 



TEANS. AM. ENT. SOC, XL. (S) 



