EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 295 



(in some of the d Scotch examj)les) with blackish grey : the brown-grey tint matches 

 with that of the wings of Cloeon simile, subimago, and the black-grey with that of the 

 fore wings of Ephemerella igniia, subimago. 



Imago {dried), d . — Notum dark pitch-brown. Setae light bistre-brown, sometimes 

 with the joinings opaque. Eore leg pitch-brown, lighter or bistre-brown towards the 

 base of the femur. Hinder legs light bistre-brown, with the knee and the tarsus pitch- 

 brown or blackish. [Living.) — Eyes very intense burnt umber-brown. Notum jet-black ; 

 a greenish-yellow or sulphur-coloured streak usually prolonged forwards from the fore 

 wing-roots strongly contrasts in colour with the dark pleura. Dorsum of abdomen 

 bistre-brown, modihed witli burut-umbcr ; segments 2-G are lighter than the remainder, 

 and have each of them the whole of the terminal margin narrowly bordered with pitch- 

 broAvn or a darker colour, a fuscous spot posteriorly on both sides, which disappears in 

 drying, and a pale space or cloud above tlie spiracular line on each side in the midst ; 

 the remaining segments likewise are paler near the same line. Venter sepia-brown, 

 tinged in the anterior segments with greenish ; the penultimate segment, tinged with 

 orange near the insertions of the forceps-limbs, has on each side a piceous lanceolate 

 wart resembling a spine. Forceps black, greyish inside distally. Setse sepia-brown. 

 Wings vitreous, with pitch-brown neuration. Pore femur fuscescent at the base, and 

 pitch-brown towards the tip ; tibia and tarsus pitch-black. Hinder legs subfuscous ; the 

 femur has a small sabrufesceut cloud nearly in the middle towards its upper edge, and 

 the tarsus is black-grey. 



$ . — Very similar to the <S . {Living.) — Abdomen more uniformly opaque than in the 

 other sex, and marked on each side, in most of the segments, either with a dark trian- 

 gular spot or an oblique dark stripe from the terminal border. Venter fuscous, with 

 greenish-grey joinings ; the terminal ganglionic mass of the nervous tract is sometimes 

 tinged faintly with warm sepia-brown. Length of body 5-9 ; wing, 6 6-10, $ 7-10 ; 

 setae, c^ im. 19, subim. 10, 2 im. 15, subim. 8 mm. 



Ilab. Locally common in the west and north of Great Britain, extending to Dorset in 

 the south. It chiefly inhabits trout-streams and the shores of lakes in hilly and moun 

 tainous districts ; and the fly appears from May to August. Nowhere have I found it 

 more abundant than it was along the shore of Ullswater, in Westmoreland, under Kail- 

 pot Crag, on 1st July. On the Continent it has an extensive range : — Styria (Brauer) ; 

 Carinthia (Zeller in M^Lacli. Mus.) ; Switzerland (Pictet and Meyer-Diir) ; Savoy, at the 

 Lac de Moutriond (3140 ft.) ; the stream below Preycinet-la-Tour (Haute-Loire) in the 

 direction of Les Estables, in company with Odontocerum (3770 ft.) ; Spain (Pwambur). 

 Small specimens of Rhithrogena semicolorcda, 2 im., are liable to be mistaken for tins 

 species, should their femoral spots happen to be indistinct ; but they are distinguishable 

 from it by their having simple, instead of branched and anastomosing cross-vciulets in 

 the pterostigmatic space of the fore wing, by the absence of the bright-yellowish streak 

 in front of the fore wing-roots, and by the ventral lobe of the 9th abdominal segment 

 being emarginate instead of seemingly subacute, or at least entire. 



