EEV. A. E. EATON OX EECENT EPHEMEfilD.E OE MAYFLIES. 273: 



posteriorly, on each side of the tract of the dorsal vessel, and another very faint triana-urar- 

 cloud of a similar tint from the hind margin of the segment, on the outer side of the streak, 

 tapering forwards, tending to enclose between them a small curved pale sjiace ; the maiu 

 tracheal trunks are greyish in segments 6-8, hut liardly perceptil)ly so in the anterior 

 segments ; segments 8-10 opaque, liglit yellow-ochre, with the vulva brown-ochreous. 

 Setae white, Avith dark joinings. AYings vitreous throughout, with the greater part of the 

 neuration piceous, but with the stronger parts of the longitudinal nervures and the great 

 cross vein of the fore wing in opaque view light dull yellowisli or yellowish grey ; in- 

 transmitted light the longitudinal neuration acquires amber-tints, while in most positions 

 the cross veinlets remain black. The markings of the hinder femoi'a are more distinct 

 than in the other sex ; and just before the extremity of tlie femur the loAver edge of the 

 limb is for a little distance black. Length of body, 6 10 ; wing, 6 11, 2 12 ; setae, S im. 

 24<, 2 im. 22 mm. 



Hub. Netherlands, near Arnhera, end of July. France, at Toulouse, July-September - 

 common near the Pont d'Empalot, and by St. Michel ojiposite the island. The newly- 

 moulted nymph is entirely light yellowish ; but on immersion in a solution of alcohol the 

 greyish-black markings become developed after death. 



Heptagexia flavipenxis, Dufour. 



XEphemera jlavqjennis, Dufour, Mem. par divers sav.aus, Instit. de France, viii. 580 note (1841). 



XBaetls longicauda, Stepli. 111. Brit. Eut. vi. 63 (ISSo) [numen iiieptiim] ; Pict., Hist. Nat. Nevropt. 

 ii. Ephem. 193 (1843-5) ; Walk., List of Neuropt. Ins. in Brit. Mus. part. iii. 560 (1853) ; Hag., Eut. 

 Ann. (1863) 24.— JB. cerea, Piet., Hist. &c. 183, pi. xsiii. 2 (1843-5) ; Walk., List. &c. iii. 558 (1853). 



Heptagenia flavijiennis, ! Etn., Trans. Ent. Soc. London (1871) 144, pi. vi. 17-17 c [details] ; !Mever- 

 Diir, Bull. Soc. Ent. Suisse, iv. 312 (1874) ; Rostock, Jahresb. d. Xer. f. Xatnrk. Zwickau, 1877, p. 90 

 (1878) ; Palmen, Paar. Ausf.-Gange d. geschl. Org. b. Insect. SS. 68, 74, 77, 78, taf. iv. 55 [anatom.] 

 (1884).— D«r. ? H. voUtans, ! Etn., Trans. Ent. Soc. London (1870) 7 ; ! id., op. cit. (1871) 147, pi. vi. 20 

 [detail] ; Rostock, Jabresb. d. Ver. f. Naturk. Zwickau 1877, p. 89 (1878) ; Palmen, Paar. Ausf.-Gange 

 d. geschl. Org. b. lusect. S. 52 [anatom.] (1884). 



Subimago {living). — Eyes and wings very similar in colour and in their developed 

 markings to those of H. snip //urea; the bullae of the costa and subcosta, and the cross 

 veinlets of the pterostigmatic region black. Femora of a light dull warm brown-ochre, 

 banded in the middle and at the tip with light reddish; tarsi and tips of tibite greyish 

 jlack. Sette concolorous with the femora, scarcely opaque at the joinings. When 

 Iried the wing-membraue is brighter than in //. sulphitrea, approaching in tint a very 

 ight shade of Mars-yellow or Italian ochre. 



Imago {dried). — Femora (or at least the fore femur) more or less faintly dark-banded 

 u the middle ; but the bauds often disappear from the hinder femoi-a of dried specimens. 

 )n each side of the metanotum, behind the upper part of the insertion of the hind coxa, 

 s a rounded black spot, which is small in both sexes. The ti-act of the dorsal vessel is 

 lot bordered ; but the extreme terminal edges of the intermediate dorsal segments are 

 ark almost from side to side. — ■ 6 {living), eyes bright or very light olive-green. Notum 

 aw-sienna or furfurosus. Dorsum of abdomen in segments 2-7 either greenish grey or 

 ght yellowish green, or light sulphureous, with the terminal margins of the segments 



SECO>D SERIES. — ZOOLOGY, VOL. III. 37 



