MORGAN HEBARD 245 



neurinae, Oxyhaloinae and Plectopterinae. At the present time we 

 do not feel justified in recognizing these, the character of the folding 

 of the distal portion of the wings being the most important factor 

 available for their separation, which, in itself, does not appear to 

 warrant such action.''" 



Of the subfamily showing few or no spines on the ventral femoral 

 margins, the Oxyhaloinae are readily separable from the preceding 

 two, the Corydiinae and Polyphaginae, by having the wings, when 

 present, with anal area folding fanwise, in this respect agreeing with 

 the Panchlorinae and Blaberinae, in which subfamilies the wings 

 are found to have the ulnar vein with numerous incomplete rami 

 and an intercalated area subobsolete or absent. 



The forms of the Oxyhaloinae never develop the very heavily 

 chitinous and robust condition typical of the two succeeding sub- 

 families, the Perisphaerinae and Panesthinae. 



The following features are considered diagnostic. Head broad, 

 ocelli indicated by spots or wholly absent. Pronotum and teg- 

 mina without hairs. Tegmina with venation distinct; with, or 

 without, '"^^ strongly developed intercalated triangle, •'"^'•* or ap- 

 pendicular field. •"'^ Subgenital plate of females simple, or with a 

 medio-longitudinal, linear cleft distad. Limbs, excluding ventro- 

 caudal margins of caudal femora, which are entirely unarmed, with 

 ventral margins unarmed except for single distal spines. "• Median 

 and caudal femora with a dorsal genicular spine. Tarsi with first 

 four joints,"- or fourth joint alone, "'^ supplied with a large pul- 

 villus. Large arolia present. 



3^^ The wings are developed as follows. The genus Oxyhaloa shows no distal field, 

 while the evidently allied Diploptera shows a greatly developed, reflexed, appendicular 

 field. The genus Chorisoneura and its allies show a decided, reflexed, intercalated tri- 

 angle, in some approaching an appendicular field. The genus Plectoptera and its allies 

 show a reflexed, appendicular field. 



3^8 Oxyhaloa and allies. 



•"^^ Chorisoneura and allies. 



3'" Diploptera and Plectoptera. 



5"' In a single apparently abnormal specimen of Chorisoneura before us, the ventro- 

 cephalic margins of the cephalic femora have each two distal spines. 



3'2 Oxyhaloa,' Diploptera. 



^'^ Ilypnorna, Chorisoneura, Plectoptera. 



MEM. AM. ENT. SOC, 2. 



