REV. A. E. EATON ON EECENT EPHEMEEID.E OR MAYFLIES. 143 



(1843-5); ^Valk., List of Neuropt. Ins. iu Brit. Mus. 582 (1853); Hag., Ent. Ann. (1863), 12; 

 Oulianine, Neuropt. & Orthopt. of Prov. of Moscow, p. 27 (1867) ; ! Etn., Trans. Ent. Soc. Loncl. 

 (1871), 95, pi. ii. 4 [ala] & v. 5 [genital. ^J] ; Hag., oj). cit. (1873), 397-9; Mocsary, Rev. d. Inhalte der 

 Termeszetrajze Fuzctek, ii. 124-5 & [German text] Naturh. Heft ii. Bd. ii. u. iii. 181-2 (1878); 

 Rostock, Jahrcsb. d. Ver. f. Naturk. Zwickan, 1877, p. 80 (1878).— C. brevkauda, ! Steph., 111. Brit. 

 Ent. vi. 01 (1835) ; Pict., Hist. &c. 280 (1843-5) ; Walk., List &c. 582 (1853).— C. peimata, ! Stepli., 

 111. Brit. Ent. vi. 01 (1835) ; Pict., Hist. &c. 286 (1843-5) ; Walk., List &c., 583 (1853).— C. ladea, 

 Gerstacker, Handb. d. Zool. ii. 01 (1803) ; Hag., Stet. Ent. Zeit. sxvi. 229-32 (1865) ; id.. Trans. 

 Ent. Soc. Lond. (1873), 397. 



Oxycypha lactea, Burm., Haudb. d. Ent. Bd. ii. Abth. ii. 796 (1839). 



?Clue horaria, Ramb., Hist. Nat. d. Ins. Nevropt. 299 (1842) ; Pict., Hist. Nat. Nevropt. ii. Ephem. 

 270 (1843-5) ; Oulianine, Neuropt. & Orthopt. of the Prov. of Moscow, p. 29 (1867). 



^Cloeon horaria, Walk., List of Neuropt. in Brit. Mus. 576 (1853). 



Subimago {Ihiug). — Wiugs greyish white, with the marginal and submarginal areas 

 tinted with warm sepia almost to their extremities. Setae white. 



Imago {living). — Head and pronotum fuscous, antennae white. Meso- and metathorax 

 piceous. Abdomen whitish, varied with grey ; iu j white above, with markings corre- 

 sponding in 2>osition with those of the ? , but only faintly tinged with grey ; in $ 

 cretaceous, with segments 1-5, and sometimes the extreme base of 6, grey above, but with 

 tlris colour broadly interrupted at the joinings by the ground-colour, and widely so iu 

 the middle of segment 1 ; moreover the patches of grey are intersected l)y a fine longi- 

 tudinal cretaceous line, and are invaded by the same colour in the neighbourhood of the 

 pleurse, where a series of grey dots is distinguishable, placed singly in the segments 

 close to their anterior lateral angles ; the dots are present also in the hinder segments, 

 which otherwise are uniformly cretaceous. The ventral segments of ? are often marked 

 on each side with a grey dot. The 6 genitalia are pale throughout, and when dried 

 have a light yellowish testaceous tint. Setae white. Eore leg in some lights tinged witli 

 Eoman sepia-grey, and with femur simply grey, becoming when dry whitish with the 

 femur bistre- or light sepia-grey in 2 , and greyish or brownish grey in d . Hinder legs 

 greyish white (the ? with yellowish-white femora when dried), with a black dot on the 

 upper edge of the femur a little before the knee, visi])le also on the ? fore femur. The 

 stronger portions of the longitudinal nervures, and the usual coloured part of the front 

 border of the wings, are greyish iu the dried s and sepia-grey in the ? . Length of 

 body 3-5 ; wings, d -4, ? 5 ; sette, 6 im. 18 & 13, subim. 3 & 2-5-3 & 3-5 ; seta?, $ im. 3, 

 subim. 2"25 millim. 



Rab. Great Britain to Moscow, and Scania (Wallengren) to Lago Maggiore, where I 

 have taken it at Pallauza. It abounds in Belgium and Holland, as well as in lowland 

 Switzerland. Pastor Wallengren adopts the prevalent surmise that this was the species 

 which Linne meant to describe as E. horaria in 1758. I have not adopted the name (on 

 account of the vagueness of the diagnosis) in the absence of authentic types. Vague 

 diagnoses are, at the most, essentially generical. 



Var. nivuLORUM. 



Imago {lioing), 2 ■ — Head and prothorax translucent whitish grey, varied with dark 



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