REV. A. E. EATON ON RECENT EPHEMERID.E OR MATTLIES. 285 



(through the obtuse angle and lower edge of the triangle being deficient in dark pigment) 

 with a broad oblique dark stripe enclosing near The posterior angle of the segment a 

 small pale space. — • d {licbig). Eyes either intense sepia-brown, traversed below by a 

 dark line edged with light yellowish or greenish grey ; or pitch-brown traversed by a 

 dark line. Frons piceous ; epistoma olive-grey or black. Notum at first bistre-brown, 

 changing to intense pitch-brown, or even to pitch-black ; a stripe in advance of the wing- 

 roots is either dull orange varied with light greenish yellow, or else subochraceous or 

 Mars-yellow. Dorsum of abdomen either light raw-umbcr-brown, or greyish bistre-brown 

 in the middle, and dull light yellowish or greenish at the sides of segments 2-6 [in the 

 hinder segments more of the former tint], with the apical borders of the segments dark 

 or piceous (excepting at the pleura?), and marked on both sides of each segment with 

 either a triangle or an oblique stripe of a reddish-brown or burnt-umber colour. When 

 there are stripes, each stripe tapers forward from a rather l)road base at the hind margin 

 to the spiracle : the stripes in segments 7 and 8 are broader than in the anterior segments, 

 and each subtends a dull light yellowish triangular spot in the hinder angle of the dorsum ; 

 this spot is almost effaced by the stripe in segment 9. The pleurae throughout the 

 abdomen and the sides of the dorsum of segment 10 in front of the insertions of the setae 

 are of a similar pale colour. Venter in segments 1-6 either light bistre-brown, olive- 

 brown, or olive-grey, becoming posteriorly more and more of a light brownish ochre or 

 dull orange ; the impressed dots and dashes are not usually dark-coloured like those of 

 E. insi(jn'is. Setae and forceps-limbs piceous. Fore femur dark bistre-brown, paler at 

 the base ; tibia and tarsus in some lights pitch-black. Hinder femora either light 

 brownish olive, light bistre, or fusco-luteovis, but pitch-brown just at the knee; tibiae in some 

 positions lighter than the femora, or even testaceous ; tarsi in some lights blackish grey 

 some or greyish black, in others pitch-black or intense sepia-brown. Wings vitreous, some- 

 times colourless, but often tinged faintly « itli greenish or yellowish green in the basal 

 half of the disk and in the greater portion of the marginal and submarginal areas of the 

 fore wing, and usually blackened or obscured with intense sepia-brown in the pterostig- 

 matic space. Neuration pitch-black, the basal extremities of the stronger nervures 

 lighter in some positions ; in living specimens the bullae are pale. 



$ (living). — Very similar to the cT but lighter. Notum bistre or light pitch-brown ; 

 tvheu dried brown-ochre or ferruginous brown. The dorsal tracheae outside the abdom- 

 inal stripes are dark. The pterostigmatic space of the fore wing is usually very slightly, 

 ifat all, discoloured, and is seldom so dark as it commonly is in the other sex; neuration 

 often pitch-brown in small specimens. Head often dull orange, with the surroundings 

 of the ocelli and a spot on the occipital margin pitch-brown, and with the epistoma 

 olive-grey ; eyes intense sepia-brown. Length of body, d 10-15, ? 10-18 ; wing, d 

 11-15, ? 11-18; seta-, d im. 22-18, ? im. 11-25, subim. 12-17 mm. 



Sab. Generally distributed from Lapland and Finmark southwards. Common in 

 Great Britain from June to September. Specimens of medium size are found in Switzer- 

 land and the adjoining districts at moderate altitudes, e. g., at Gex and Berne (M°Lach.) ; 

 also near Samoens at 2200 ft., and near Bannio, Val Anzasca, at 3000 ft., and near 

 Fontana, Val Bavona, not far from Bignasco, at about 2000 ft. Similar specimens have 



