256 KEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 



middle : egg-valve darker than the neighbouring parts ; lobe of the 9th ventral segment 

 entire. Legs of a greener tint than in the d ; a dark longitudinal streak nearly in the 

 middle of the inner side of the fore femur ; the hinder tibite whitish basewards, but 

 distally, like the tarsi, dusky. Pterostigmatic region very faintly tinted with dusky ; 

 tegulse more or less yellowish. Length of body 8-5 ; wing, d 10, 9 11 ; setse, d im. 

 20-25, ? im. 17 mm. 



Mab. Switzerland, Savoy, and North Italy ; July to September. Alpbach, Meyringen 

 (1 subim. 15th August, M'Lach.); common near the Chalets de Pas, Champery (57GOft., 

 5 P.M., 20th August, water 51° F.) ; very common in the vicinage of Charbonni^re, about 

 the head-waters of the Dranse de Biot (4300-1800 ft., 1-5 p.m., 2nd Sept., water 62° to 

 48" F.) ; also singly by the Oglio in the Val Mazza above Ponte di Legno (5800 ft., 

 4.46 P.M., 29th July, water 49° to 56° F.). 



RniTnKOGENA HYBUIDA, Sp. nOV. 



Imago (dried), 6 . — Notum black. Dorsum of the abdomen pitch-brown. Setse light 

 warm sepia-brown with slightly opaque joinings. Fore leg pitch-brown or intense bistre- 

 brown : hinder femora in opaque view uniformly of a reddish brown, the tibiae lighter and 

 of a rather yellower brown in some postures, and the tarsi slightly greyish ; no femoral 

 markings. The colouring of the wings in its distribution conforms to that of Variation 1, 

 of Eh. semicolorata, but is of a duller hue, being light bistre-brown instead of raw-umber. 

 Wing-neuration, in opaque view, entirely pitch-brown, excepting that the sector (4), 

 cubitus, brachial, and anal (8) nervures of the fore wing are deficient in colour at the 

 extreme roots where they meet the raised fold in the membrane. Length of wing 9-10 mm. 



Sab. Savoy, in the neighbourhood of Samoens ; common about the head-waters of 

 the Dranse de Biot, near Charbonniere (4780 ft., 10 a.m., 12th August) ; also near the 

 Chalets do Jouplane (5100 ft., 9.30 a.m., 29th August, water 52° F.). Easily mistaken 

 for the following species ; but the absence of femoral markings, and the uniformly 

 dark colour of the subcosta and radius of the fore wing seem to necessitate their 

 separation. 



RniTnuoGENA semicolorata, Curtis. Plates XXIII. 43 [& virtually 44] (wings), XXIV. 

 43 (legs), & 43 '"' (penis). Nymph Plate LIV. 3, 4. 



? {Ephemera] or E. sticjma [Zsch. Mas. Lesk. i. 150, no. 20 (1789) ] ; Gmel. Liim. Syst. Nat. ed. 

 xiii. i. pars v. 2G30 (1790) ; 01., Eucyc. Metli. vi. 423 (1791).—? E. fuscula, Schrank, ¥n. Boica, ii. 

 199 (1708). 



t Baetis semicolorata, Curt., Lend. & Edinb. Philos. Mag. scr. 3 (1831) 131; ! Steph., 111. Brit. Eot. 

 vi. 61, pi. xxix. 2 (183.5) ; Pict. Hist. Nat. Nevropt. ii. Eplie'm. 178, pi. xxii. 4-9 (1843-5) ; Walk., List 

 of Neuropt. Ins. in Brit. Mus. part iii. 577 (1853) ; Hag., Ent. Anu. (1863) 36.— J B. semitinda, Pict., 

 Hist. Nat. Nevropt. ii. Ephem. 180, pi. xxii. 1-3 (1843-5) ; Walk., List &c. part iii. 558 (1853); Brauer, 

 Neuropt. Austr. 26 (1857) ; Ausser., Ann. d. Soc. Natur. Modena, An. iv. 133 (1869) ; Etn., Trans. 

 Ent. Soc. London (1871) 36, note. 



Heptayenia semicolorata, ! Etn. Trans. But. Soc. London (1871) 136, pi. vi. 9 [detail] ; Hag. & Etn., 

 op. cit. (1873) 403; Mcyer-Dur, Bull. Soc. Ent. Suisse iv. 311 (1874) ; Rostock, Jahresb. d. Ver. f. 



