MORGAN HEBARD 199 



A. Sinistral genital hook strongly recurved distad to the acute apex. 



B. Dextro-ventral genital plate rotundato-quadrate, not showing deep 

 emargination. Dextro-dorsal genital plate small, but with- sinistro- 

 distal portion produced and lobate. 

 C. Surface of dextro-ventral genital plate concave, distal margin very 



broadly and conspicuously shagreenous 1 . boUiana (Saussure) 



CC. Surface of dextro-ventral genital plate weakly concave, distal 

 margin very narrowly and weakly roughened or smooth. 



2. rehni Hebard 



BB. Dextro-ventral genital j^late cleft to near base dextrad, the sinistral 

 portion rotundato-rectangulate and longer than broad, the distal 

 margins smooth, the dextral portion a stout chitinous rounded pro- 

 jection, which curves sinistrad, with apex touching the dextral margin 

 of the sinistral portion mesad. Dextro-dorsal genital plate relatively 

 very small, narrowly transverse, with exj^osed surface rounded. 



3. grata new species 



AA. Sinistral genital hook barbed distad, like a fish-hook, and in consequence 

 slightly thicker above the barb than in meflian portion of shaft. 

 B. Dextro-ventral genital plate without projections. 



C. Dextro-dorsal genital plate small and sausage-shaped, with ventral 

 surface concave and in consequence separated a uniform and con- 

 siderable distance from the dextro-ventral genital plate. (Dextro- 

 ventral genital plate small, with margins rounded and surface 



smooth.) 4. floridensis Caudell 



CC. Dextro-dorsal genital plate with ventral surface not concave and 

 partially in contact with dextro-ventral genital plate. 

 D. Dextro-ventral genital plate vertically broad, with margins rounded 

 and surface smooth 5. erratica Rehn 



6 The intricate character of the dextral genital plates is by no means fully 

 characterized in this key. We here attempt to describe only those portions 

 which are visible when the subgenital plate has been removed. These, we 

 believe, are quite sufficient for specific determination. The portions of these 

 plates which are concealed when in normal position, will afford an interesting 

 subject when detailed studies of the genitalia are made, but should not be 

 added to the diagnoses, already intricate, necessary for purely systematic 

 purposes. In our dissections we have found that the dextro-dorsal genital 

 plate is always produced in a long narrow curving process which, directed 

 ventrad along the dextral wall of the anal chamber, connects with the dextro- 

 ventral plate near its basal portion dextrad. Moreover the dextro-dorsal 

 plate is, at least In some species, produced inward from its sinistro-basal 

 portion (see plate VII, figures 15 to 17), while in others the dextro-ventral 

 plate has an appendage sinistrad, which, while usually concealed, must not be 

 mistaken for an abnormality when visible (see plate VII, figure 7A). 



TRA.XS. AM. ENT. SOC, XLVI. 



