186 EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MATELIES. 



the radius and the sector, is of a browu amber-colour, or light fuscous, excepting along 

 the borders of the cross veinlets, where it remains pellucid and white ; the costa, sub- 

 costa, and radius are concolorous with the membrane, excepting sometimes the subcosta 

 and the radius near the wing-roots, where, with the great cross vein, they are often fvxscous 

 or piceous ; the cross veinlets in advance of the sector, including those also in the sub- 

 marginal and marginal areas, are opaque Avhite ; the remainder of the neuration is 

 piceous, excepting sometimes that the cross veinlets nearest the wing-roots and posterior 

 to the pobrachial nervure (7) are also white ; the cross veinlets in the disk of the wing 

 are much stouter than the nervures in this sex. Length of body, d 5-10, ? 8-11 ; 

 wing, cf 6-11, ? 9-12 ; setae, 6 im. 13-20, subim. 9-14, ? im. 12-15, subim. 12 

 mm. 



Hub. Europe, from Scania and Norway (Wallengren) southwards to the borders of the 

 Euxine and Mediterranean ; Madeira, in pools left in the lower parts of the beds of 

 streams in the neighbourhood of Funchal (22 Nov. 1880), first collected by Wollaston ; 

 TenerifFe, common near the Jardin Botanico, Orotava (15 Dec. 1880) ; Egypt (Savigny, 

 and F. Walker !) ; Armenia (Hag. Mus.) ; Japan (M^Lach. Mus.). In Great Britain, 

 clean ponds that acquire a rather high summer temperature are frequented by this 

 species ; at Paris, tanks for Nymphfeacese and other water-plants in the Jardin des Plantes 

 are its favourite resorts. Hitherto instances of viviparation on the part of C. dipterum 

 have been observed only in the warmer parts of Italy and France. 



The occurrence of species closely related to C. diptertmi in N.W. India, and in the 

 Knysna, S. Africa, was recorded by me in Trans. Ent. Soc. Loudon (1871), p. 103; there 

 is also one in Australia. 



CLOiiON SIMILE, Etn. Plates XVII. 31 b (adult wing, d legs and forceps), XLVII. no. 2 

 (details of nymph). 



Che II obscura, ! Ramb., Hist. Nat. d. Ins. Nevropt. 297 (1842). 



Clo'con II obsmrum, ! Etn., Trans. Eut. Soc. London (1871) 104. — C. simile, ! id., op. cit. (1870) 2; \id., 

 (1871) 103, pis. ii. 7 & V. 11 [details]; Rostock, Jaliresb. d. Ver. f. Naturk. Zwickau, 1877, 81 (1878). 



Subimago {living). — Wings mouse-grey, tinged with yellowish in a slight degree along 

 the costa and at the base ; the nervures somewhat raw sienna in colour. Setae piceous. 

 Oculi of <s subolivaceous. 



Imago {living). — <3 . Turbinate eyes olivaceous or dark greenish sulphureous; lower 

 eyes either joitch-black or greenish black. Notum either jet-black or fuscous. Abdomen 

 pitch-brown above ; venter cinereous, faintly tinged with yellowish towards the tip. Setae 

 rusty white, with reddish joinings. Forceps greenish white ; the limbs nearly contiguous 

 at the base ; penis-cover (or penis ?) gently curved distally, not acute like that of 

 C. dipterum. Legs olivaceous with greyish or blackish tarsi ; the fore tibia greenish 

 grey. Wings vitreous ; the subcosta and radius of the fore wing somewhat straw-colour 

 or bright amber-yellow ; the pterostigmatic portion of the marginal area contains nume- 

 rous (about 9-11) cross veinlets, slightly irregular in their curvature and sparingly 

 conjoined ; there are none before the bulla in either sex. 



? . Eyes black. Head castaneous in the vicinage of the ocelli, with two longitudinal 



