EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 189 



cent white, with the edges of the dorsal vessel, a spot on each side of it on every joining-, 

 and a clond over the tracheal ramifications, dull reddish ; the tracheal trunk pitch- 

 black ; segments 7-, or 8-10, above, either pitch-brown, or fusco-luteous, or fuscous, or 

 almost burnt-sienna red, sometimes with the joinings ochraceous ; venter in segments 7- 

 10 ochraceous Avhite, sometimes with a pair of abbreviated dark lines beneath the 

 ganglionic cord at tlie base of each segment but the last, and with a dark line immedi- 

 ately beneath the spiracular ridge. Eorceps and setge white. Legs either wholly white, 

 or with the fore femur greenish grey, the fore tibia and tarsus grey or greyish white, 

 the hinder femora white tinged with very light yellow or sulphureous, and the hinder 

 tibiae and tarsi dull white. Wings vitreous ; the marginal area in its pterostigmatic 

 portion contains 6-8 oblique cross veinlets, sometimes sparingly forked near the sub- 

 costa ; there are none before the bulla in either of the sexes. 



$ (liviny). — Eyes caisious, or dark olive-grey, or light greenish grey, or brown-black. 

 Vertex of head light yellow, with a double longitudinal median reddish or brown-ochreous 

 stripe from the frons to the occipital mai-gin. Thorax above sometimes very light dull 

 brown-ochre, sometimes very light yellowish, sometimes bistre-brown, sometimes jet- 

 black ; the peak of the mesonotum often tinged with bright green. Abdomen sometimes 

 fuscous, sometimes olive-grey, sometimes in such examples tinged distally with light 

 brown-ochre, and sometimes uniformly of this last colour : the lighter segments (2-7) 

 either have each a small spot in the middle, two at the apical margin, and an indistinct 

 curved line on each side of the back, or have a small spot in the middle of the back, and 

 a larger triangular spot on each side distally, of the same yellowish or furfuraceous 

 colour ; the subcutaneoi;s tracheae, and a streak close by every spiracle, are black. 

 Venter lighter tlian the dorsum, and sometimes paler anteriorly than in the hinder 

 segments, sometimes reddish white. Setse white. Fore femur sometimes greenish- or 

 olive-grey ; hinder femora greenish white ; tibiae and tarsi white, with the terminal tarsal 

 joints cinereous. Wings vitreous, often tinged at the base with bright green. Length 

 of body 5-9 ; wing 6-10 ; setse, <s im. 13-15, subim. 9, ? im. 10-12, subim. 6-8 mm. 



Hah. Europe from Scania (Wallengren) and Great Britain to Switzerland and southern 

 France ; profusely abundant in Holland near Gouda &c. and in Belgium ; common in 

 Saxony (Rostock) ; also at Basle (M^Lach.), near Visp in Canton Valais ; and in the 

 leighbourhood of Orthez in the Basses Pyrenees. The forceps-limbs are wider apart 

 it the base than in our other native species, and their terminal joints more slender. 

 The identity with this species of the Chinese specimen referred to below is open to 

 luestion. 



^LOEON siNENSE, Walker [Catalogue-name only]. 



X Ctsnis sinensis, ! Walk., List of Neuropt. Ins. in Brit. Miis. part iii. 584 (1853). 

 Cloeon X russulwm, ! Etn., Trans. Eut. Soc. London (1871) 105, var. 2 [part.]. 



Hab. Northern China. A single adult 6 in the British Museum, insufficiently 

 escribed, is very similar to, if not identical Avith, C. rufulum. 



