EEV. A. E. EATON ON KECENT EPHEMEEID^ OR MAYFLIES. 283 



greenish or yellowish ; they also exhibit a movable black spot. Notum either testaceo- 

 piceous or pitch-black. Dorsum of abdomen either dark l)istrc-bro\vn or rufo-piceous, 

 with the terminal borders of the segments opaque, having, however, their extreme edges 

 sometimes pale, and with small translucent markings at the bases of some of the segments, 

 similar to those already described in dried specimens. Venter sometimes uniformly dark 

 warm-sepia, sometimes a rather yellower brown with paler joinings; segment 9 tinged 

 with dull orange, and edged at the extreme base and at the sides with pitch-black ; a 

 pair of abbreviated divergent black lines is apparent at the base of the segment in 

 segments 2-8, and the nerve-ganglia are visibly darkened in segments 4-7. Forceps- 

 basis olive-black ; the limbs black, each with a whitish spot inside at the base of the 

 penultimate joint, and with the terminal joint wdiite inside. Seta3 pitch-black at the 

 base, becoming distally light dusky grey with darker joinings. Pore legs pitch-black, 

 Avith the femora lighter towards the base, and with the tarsal incisures whitish beneath. 

 Hinder femora light olivaceous, tinged with bistre towards the knee ; tibia3 light oliva- 

 ceous, tinged with smoke-grey distally, [with change of light a yellowish tint predom- 

 inates over the olive] ; tarsi pitch-black, with the joinings pale beneath. Wings vitreous ; 

 the fore wing often tinted conspicuously towards the roots and in the marginal and sul> 

 marginal areas with dull gi'eenish yellow, or with yellowish green, and blackened or dark 

 grey in the pterostigmatic region ; neuration for the most part pitch-black, excepting 

 that the stronger nervures in the disk are tinged with fuscous, and become near the roots 

 olivaceous or flavo-piccous. 



2 (dried). — Very similar to E. venosus 2 . Length of body 10-13-5 ; wing, 6 12-13, 

 $ 13-15: seta?, 6 im. 25-35, subim. 15, ? im. 21, subim. 14 mm. 



Hab. Alpine Switzerland, N. Italy and Savoy, chiefly at altitudes of over 2000 ft. 

 Common in July and August at the following localities : — the head-waters of the Dranse 

 de Biot near the Charbonniere at 4800 ft., and (in the same neighbourhood) both near the 

 Chalets de Jouplane, Samoens, at 5100 ft., and near Bonavaux, Champery, at 5400 ft. ; 

 also in Val Furva near Bormio at 6300 ft., and in tlie neiuhbouriug Mt. Adamello district. 

 Streams and torrents ranging in temperature at the stated season from 50° to 02° F. 

 seem to be the most suitable for the species, although it may sometimes be met with 

 where the temperature of the water in the morning is as low as 46° F., or as high in the 

 afternoon as 68° F. Mr. M''Lachlan captured several specimens of this species near 

 Interlaken in the Habkern Thai, on the 21st of August ; and I am disposed to identify 

 with it a specimen captured by me in the Apennino Pistojese, at 4200-5200 ft., in the 

 Valle Sestajoue. 



[ECDTTOUS VENOSUS, Fabricius. Adult, PI. XXIII. 40 (liind wing) ; PL XXIV. 46 

 (legs and genitalia). Nijmph, PI. LXII. 

 Ephemera venosa, Fabr., Syst. Ent. .304 (1775); if/., Sp. Iiis. i.3Sl (1782); jrf., Maiit. Ins. i. 2^13 

 (1787) ; Gmel., Linn. Syst. Nat. cd. 13, i. pars v. 2G29 (1790) ; Ol., Encycl. Meth. vi. 418 (1791); Fabr., 

 Eut. Syst. iii. pars i. 70 (1793) ; Lat., Hist. Nat. d. Crust, et lus. xiii. 97 (1805). — E. berolinensis, 

 MiilL, Zool. Dan. Prodr. 143 note (1776) ?—E. fusco-grisea, Retz., C. de G. Gen. et Sp. Ins. no. 183 

 (1783) ? — E. nervosa, YilL, C. Linn. Eut. iii. 22 (1789). — E. nigrhnana, Dufour, Mem. par divers sav., 

 Instit. de France, %-iii. 580 footnote (1811) ?— £. rufa, Ramb., Hist. Nat. d. Ins. Nevropt. 269 (1842). 



38* 



