EEV. A. E. EATON ON RECENT EPHEJIERID^ OE MAYFLIES. 69 



the cross veinlets is generally narroAV, but in the midst of the wing the edging of about 

 half a dozen veinlets or more is enlarged into small spots. 



Variation. — In the fore wing the fascia is virtually resolved into its comj)onent spots, 

 the other spots are reduced in size, the bordering of the cross veinlets is much restricted 

 and scarcely any^vhere guttulate ; in the hind wing the terminal margin is not bordered 

 with the faint greyish cloud, the spots are rudimentary or reduced to two or three in the 

 midst of the disk, and many of the cross veinlets are not dark bordered. 



? {dried and in spirits). — Very similar to the 6 , but with the latero-dorsal blotches 

 more nearly resolved into a pair of separate triangular streaks on each side of segments 

 3-6, the blending of those in the other segments corresponding with what is usual in 

 the other sex. The wings are rather clearer than is customary in the s , especially in 

 the pterostigmatic region, and the edging of the cross veinlets is rather less distinct. 

 Fore legs light rufo-piceous with the femur and tip of the tibia darker ; the tarsal joints 

 lighter towards their bases. Hinder legs as in the c? , but the tibia and tarsus slightly 

 redder than the femur than yellower. Setse light burnt-timber brown, with pitch-brown 

 joinings. 



Variation (probably killed before attaining maturity of colouring). — Thorax brown- 

 ochreous : fore femur light bistre-brown, the tibia and tarsus rather lighter, but with the 

 ungues, the tips of the intermediate and first tarsal joints and also of the tibia dark 

 burnt-umber brown. Hinder legs in opaque view with the femur light greenish bistre- 

 grey, and the rest lighter, changing in transmitted light to greenish amber and light 

 yellow amber. Abdominal markings as in the c? . 



Variation. — Colour of legs, thorax, and wings, normal ; but differing in the dorsal 

 markings of the abdomen. In segments 3-6 only the upper triangular streak of every 

 latero-dorsal blotch is present on each side, the lower is absent (perhaps owing to the 

 ravages of Anthremts): a short linear black streak is produced forwards along the 

 spiracular margin from the posterior lateral angle of the dorsum of each of these 

 segments. This is the variation simulating E. vulgata mentioned by Hagen. Length 

 of body, 6 11-13, ? 13-15 ; wing, 6 12-11, ? 15-19 ; sette, 6 im. 25-32, submi. 14, 

 ? im. 16, subim. 15 mm. 



Rab. North America, from Akhurst, Virginia, to St. Martin's Falls, river Albany, 

 Hudson's Bay, and from West Beach, Maine, to Saskatchewan. This species swarms 

 yearly at Chicago, 111., at street lamps, about the third week in July. A tube fuU of 

 specimens collected at an island in Lake Erie, near the mouth of Detroit river, by Mr. 

 Scudder, is dated 21th July. 



Ephemeha varia (renamed). Plate LXIII. 12 h (forceps). 



Ephemera % decora, ! Hag., Smithson. Miscell. Coll. (1861), Synop. Neuropt. N. Am. 38 ; idem, ! Ann. 

 Rep. U. S. Geol. and Geograph. Survey of the Territ. 1873, part iii. Zool. 578 (1875). 



Suhimago {dried), <5 .—Wings translucent, very light grey or whitish grey, the sub- 

 marginal area of the fore wing before the pterostigmatic space shghtly yellowish : neura- 

 tion partly Light and partly dark, the longitudinal nervures of the fore wing to a great 



