KPHEMERIDifi. BAETIS. 63 



A. Wings very distinctly and rather thickly reticulated. 



Sp. t- dispar. Pallide castanea, abdominis segmentorum marginibus hrunneis, 

 alis hyalinis, casta Jlavescente ante apicem fuscescente. (Exp. Alar. 14lin. ; 

 Long. corp. 5| — 6 lin. ; 1. set. 16 — 17 lin.) 



Ba. dispar. Curtis, v. xi. pi. 484. — Steph. Nomen. 2d edit. Appendix. 



" Pale castaneous : eyes and disc of thorax sometimes much darker in the 

 male; segments of the abdomen with the margins brown, filaments more 

 than twice as long as the insect ; tibiae, excepting the anterior pair, ochreous 

 towards the apex ; tarsi fuscous ; wings transparent, anterior pale yellow 

 at the base in the male, as well as the costal margin, which is pale brown 

 towards the apex, nervures of the same colour. 



" The wings in the pseudimago — a term employed by Mr. Curtis — have all the 

 nervures suffused with fuscous, and the costa not darker than the rest of the 

 wing." — Curtis, I. c. 



Found, but rarely, in the vicinity of London, in June : also taken 

 in the north of England. 



Sp. 2. venosa. Obscure fusca, alis albis, nervuris fuscis. (Exp. Alar. 15 lin. ; 

 Long. corp. 6 lin. ; 1. set. 8 lin.) 



Eph. venosa. Fabricius. — Ba. venosa. Steph. Catal. 366. No. 3389. 



Dull fuscous : wings broad, white, with fuscous nervures. 

 Probably a variety of the foregoing species ; but the wings are much broader, 

 and the filaments shorter. 



Found near London, in June. 



Sp. 3. longicauda. Ochraceo-lutea, pedihus pallidioribus, geniculis abdomi- 

 nisque segmentorum marginibus fuscis, setis longissimis. (Exp. Alar. 14 lin.; 

 Long. corp. 5^ lin. ; 1. set. 14^ lin.) 



Ba. caudata. Steph. Catal. 366. iVo. 3388. 



Pale luteous-ochre : eyes fuscous ; thorax glossy ; abdomen pale ochreous at 

 the base, the apex darker, the segments edged with fuscous ; filaments 

 considerably above twice the length of the insect, pale ochreous, with faint 

 fuscous spots ; legs pale ochreous, tips of femora fuscescent ; wings trans- 

 parent, with the costa and nervures yellowish. 



Pseudimago ?— Ba. mellea. Curtis, Phil. Mag. 1834. 



"Bright ochreous : eyes black ; segment of abdomen edged with brown, with 

 a trigonate brown mark on the back of each, and the spiracles forming a 

 double row of black dots down each side ; filaments longer than the insect' 

 dotted with brown; wings pale yellow, costa a little darker, nervures 

 yellow and brown." — Curtis, I. c. 



Taken near Hertford, towards the middle of June. 



