— 242 - 



2 (1). Articiiliis basalis palporum simplex, proboscis in parte an- 

 tica capitis inserta et oculi in utroque sexu fusco-rubescentes : anten- 

 narum articulus primus niger vel nigricans. 



3 (4). Nervus subcostalis apicem versus evanescens, spurius, vix 

 distinctas; maris genitalia perparva, lamella supera nigra forcipem 

 omnino includente; nervi transversi distantes ; colores valde infuscati, 

 fei-e nigri nigra. 



4 (3). Nervus subcostalis in medio tantum spurius, ad apicem inte- 

 ger et distinctissimus ; maris genitalia persaepius mediocria vel magna, 

 forcipe plus minusve prominente ; colores lutei vel testacei^ rarissimo 

 nigri. 



5 (6). Alae distincte infuscatae ; nervus subcostalis apicem versus 

 satis exilis ; nervus primus longitudinalis brevior quam in sequentibus, 

 ideoque costae segmenta secundum et tertium subaequalia ; nervi trans- 

 versi approximati ; corpus fusco-rubescens, fere nigricans ; genitalia 

 maris parva . subafricana 



6 (5). Alae vix infuscatae^ ex cinereo-hyalinae ; nervus subcostalis 

 apicem versus validus ; nervus primus longior, costae segmento secundo 

 circiter tertio sesquilongiore. 



7 (14) Genitalia in utroque sexu mediocria vel parva, in mare la- 

 mella snpera rotundata, vel hemisphaerica, nunquam producta, forcipe 

 parvo vel mediocri lamella non aut pauUo longiore et articulis basi- 

 saepius approximatis; in foemina lamellis basalibus parum evolutis, 

 indistinctis vel brevibus. 



8 (13). Species minores (2-3,5 mm.), pallidiores, alls brevioribus 

 (3p-4,5 mm.) praeditae ; pili totius corporis breves ; coxae lutescentes; 

 nervi transversi plerumque approximati ; maris forceps brevis, articu- 

 lis basalibus approximatis ; foeminae abdomen apice simplex. 



9 (10). Maris lamella supera nigra, parva, cylindro-conica, infra 

 involuta, forcipem perpavum omnino includens ; alarum nervi trans- 

 versi distantes et tertius longitudinalis totus rectus in alae apicem de- 

 sinens ; species nearctica americana. 



10 (9\ Lamella supera lutea, satis magna, rotundata vel hemi- 

 sphaerica; forceps mediocris, plus minusve exsertus; alarum nervi trans- 

 versi approximati et tertius apicem versus intra incurvatus, panilo 

 post alae apicem desinens ; species palaearcticae. 



11 (12). Maris forceps brevior quam lamella supera et articulo ba- 

 sali valde inflato, rotundato, praeditus inflata. 



12 (11). Maris forceps lamella paullo longior, articulo basali parum 

 inflato, cylindrico testacea. 



13 (8). Species major (4-5,5 mm.), fere nigra, alis longioribus 

 (5,5-7 mm.) ; pili longiores ; coxae nigricantes ; nervi transversi dis- 

 tantes ; forceps satis elongatus, articulis basi distantibus et lamella 



