270 REV. A. E. EATON ON RECENT EPHEMElilD.E OR MAYFLIES. 



black spot or streak. Dorsum of abdomen in segments 2-7 either very light olive-green 

 or light gamboge-yellow, but in segments 8-10 light yellow or yellow-ochre ; the terminal 

 borders of the segments narrowly fuscous ; venter spotless. Setce white or greyish white, 

 with dark or rufescent joinings. Legs gamboge- or amber-yellow ; the tarsi greyish white> 

 with black joinings. Wings vitreous ; the fore wing usually tinged only in the marginal 

 and submarginal areas with lemon-yellow, but sometimes a fainter tint of the same colour 

 suffuses the remainder of the membrane universally ; neuration mostly black, but the 

 stronger portions of the longitudinal nervures, the great cross vein, and the axillar fold 

 are gamboge- or amber-yellow. In dried specimens the notum becomes light brownish 

 ochre, instead of fuscous, along the middle, and in many positions the longitudinal 

 neuration of the wings becomes amber-yellow, while the cross veinlets remain pitch- 

 black or black ; the colouring of the wing-membrane in the marginal and submargiual 

 areas of the fore wing of ordinary specimens becomes brownish amber, and is most 

 apparent only in the sul)marginal area and in the pterostigmatic portion of the marginal 

 area, though not entirely deficient in the remainder of the former area. 



Variation, <S im. [dried). — The abdomen is almost uniformly light pitch-brown 

 (excepting, as usual, tbe terminal edges of the dorsal segments), and the tract of tlie 

 dorsal vessel is subopaque, but not so dark as to be reckoned as a dark dorsal stripe. 

 Hah. Ponte de Morcellos (Beira Baixa), Portugal. 



Length of body, 6 7-10, 2 9-11 ; wing, d 8-5-12, ? 11-13 ; seta?, cJ im. 16-23, 

 2 im. 14-19, subim. d & ? 12-15 mm. 



Hah. Generally distributed in Eui'ojje in streams and the swift parts of rivers from at 

 least Hammerfest to the south of Prance and northern Portugal, and from Great Britain 

 to southern Russia. May to September. In Brauer's description of the 6 fore tarsus 

 " dritte " is written for " vierte." 



Heptagenia cJiiRULANS, Rostock. 



Heptagenia C(erulans, ! Rostock, Jahresb. d. Vcr. f. Naturk. Zwickau, 1877, p. 89 (1878). 



Imago. — " Thorax yellow-brown, darker behind. Abdomen brown above, darker at the 

 tips of the segments, ochreous at the sides and beneath, and tinged with orange in the 

 last three segments. Forceps brownish. Setse smutty-white, annulated with darker 

 towards the tips. Pore leg of <3 testaceous-brown, with darker joinings. Pore wings 

 with bluish iridescence, the marginal area eitlier colourless or, at the most, tinged with 

 yellowish at the apex. Expanse of wing 21 ; length of setiE, 6 im. 25 mm." [After 

 Eostock.] 



Hah. TVeisseritz, near Dretschen, Saxony (Rostock). I have had no recent opportunity 

 of comparing this species with H. gallica. As nothing is said by Herr Rostock of any 

 spot at the side of the metanotum, or of any dorsal abdominal stripe in H. ccsrulans, I 

 Lave supposed them to be distinct species. 



Heptagenia flava, Rostock. 



Heptagenia flava, ! Rostock, Jahresb. d. Vcr. f. Naturk. Zwickau, 1877, p. 90 (1878). 



