EEV. A. E. EATON ON EECENT EPHEMEEID^ OE MAYFLIES. 217 



Imago {dried), d . — Thorax luteo-piceous above. Abdomen fuscous above, with the 

 joinings paler towards the sides ; venter lutescent or ochraceous, with U-shaped dark 

 marks in the hinder segments. Forceps piceous. Setoe either of the very lightest 

 warm sepia-grey, or faintly tinged with fulvous ; the joinings fuscous. Fore legs piceous ; 

 hinder legs lutescent or ochi'aceous. Wings vitreous tinted with greenish grey ; their 

 neiu'ation piceous. Length of body 14-15 ; wing 15-16 ; setoe, d im. 24-25 mm. 



Sab. England and Ireland : Eallarney (M°Lach. Mus.;; Bishop's Wood, Hampstead, 

 Middlesex (Wormald), in July. 



SiPHLTJBUS LACUSTEis, Etu, Plate XX. 34 d (head <j , legs, and forceps). 



Siphlurm lacustris, ! Etu., Trans. Ent. Soc. Loudon (1870), 7; \ id., op. cit. (1871), 126, pi. vi. 2 

 [detail] . 



Sublmago {liciug). — Wings cinereous or very light sepia-grey. 



Imago {living), 3 . — Eyes dark sepia-brown above, dark greenish grey beneath. Thorax 

 jet-black above, pitch-brown when dried. Abdomen piceo-fuscous above, with ochraceous 

 joinings ; venter dai'k greenish-grey, becoming fulvescent in the last three segments, 

 which are marked each with a dark U-shaped streak, represented in every anterior 

 segment by two dark longitudinal stripes, convergent towards the base of the segment. 

 In dried examples of what I suppose to be the same species the venter becomes yellowish 

 brown, with pale joinings, and the dark markings are sometimes absent. Forceps-limbs 

 bistre-brown. Sette sepia-brown at the base and greenish grey elsewhere, with opaque 

 joinings ; when dried light burnt-umber brown. Legs yellowish brown in dried examples ; 

 in life the fore femur is black-green, the tibia and tarsus greyish black, and the hinder 

 legs are dark greenish grey. Wings vitreous, with piceous neuration ; the pterostigmatic 

 region of the fore wing is faintly tinted with pale greenish. 



? . Similar, but with sepia-brown setse, and with the hinder tibise and tarsi light 

 brown-ochraceous. Length of body or wing 12-15 ; setce, $ im. 17-20, subim. 11 ; 

 ? im. 16-18 mm. 



Sab. Great Britain : Llyn Llydaw, Snowdon ; streamlets or small burns in the neigh- 

 bourhood of Corse, near Lumphanan, Aberdeenshire ; in August. Also the Giffre, near 

 Samoens, Savoie (2280 ft.), in September ; also near San Marcello in the Apennino 

 Pistojese (about 2500 ft.) in August. 



5IPHLUIIUS LlNN^ANIJS, Etu. 



SipUurus Linnceanus, ! Etu., Trans. Ent. Soc. London (1871), 127, pi. vi. 3, 3a [detail]. 



Imago {dried), 6 . — Thorax above bistre-brown in front, varied with light reddish ochre 



iehind. Abdomen along the middle of the back broadly fuscous, darker at the tips of 



he segments, light ochraceous at the sides, the dark colour extending forwards at the 



ides in segments 2-9 so as to restrict the paler colour to a triangular patch above the 



piracxilar line ; venter in segments 2-8 light ochraceous marked with black, viz. ; — with 



le joinings of segments 2 and 3, and in each of segments 2-8 a short triangular streak 



•om the middle of the base, pointing backwards, followed by a transversely placed pair 



SECOND SERIES. — ZOOLOGY, VOL. III. 29 



