548 EPHEMERIN.E. 



21. POTAMANTHUS HALTERATUS. 



Fuscus ; abdomen album, apice fuscum; pedes antici albi ; seta 

 corpore quadruplo longiores ; ala alba. 



Ephemera halterata, Fabr. Ent. Syst. ii. 69, 6. 

 Potamanthus halteratus, Pictet, Hist. Nat. Neur. Eph. 236. 



Europe. 



22. Potamanthus minor. 



Obscure fuscus, segmentorum marginibus rufescentibus ; pedibus 

 pallidis ; alls angustis hyalinis costa concolore. 



Ephemera minor, Steph. III. Brit. Ent. Mand. vi. 60, 16. 

 Potamanthus minor, Pictet, Hist. Nat. Neur. Eph. vi. 237. 



England. 



23. Potamanthus ? costalis, Mas. 



Niger ; thoracis linea ante alas albida ; abdomine pedibusque 

 rufo cingulatis ; ala subfumata, venis omnibus areola margi- 

 nalis \a et 2a infuscatis. Long, 6 lin. 



Baetis costalis, Burnt. Handb. Ent. ii. 800, 2. 



Potamanthus ? costalis, Pictet, Hist. Nat. Neur. Eph. vi. 237. 



New Holland. 



P. costalis ? Fem. Nigro-picea, Jlavo guttata ; thorax rufo-bivit- 

 tatus ; abdomen rufo varium ; seta picea ; pedes rufi, femoribus 

 piceo bifasciatis, tarsis piceis, antici picei, femoribus rufo fas - 

 ciatis ; ala limpida, venis costalibus nigro-nebulosis. 



Fem. — Piceous black : head and thorax with pale yellow dots : 

 head reddish on each side : antennae black : thorax with an indis- 

 tinct reddish stripe on each side : abdomen with some reddish 

 marks, about twice the length of the thorax : seta? piceous : legs 

 red; femora with two piceous bands; tarsi piceous: fore-legs 

 piceous, with a red band near the tip of each femur : wings quite 



