EEV. A. E. EATON ON EECENT EPHEJMERIDiE OR MAYFLIES. 31 



nab. Brazil {Pict.), Rio Mauhes, "at light," 5tli May, 1874, and Rio Jutahi, "at 

 light," 1st to 5th Fehruary, 1875 {Trail) ; both sexes ia M^Lach. Mus. The cross veinlets 

 in the marginal area of the fore wing are not easily discovered in a dried wing ; and those 

 in the space behind the nervure numbered 3 in my figure vary within two or three of the 

 number (six) quoted. The dimensions of the ? in M°Lach. Mus. are identical with 

 those stated by Hagen. 



Oligonetjria rhenana, Pict. Plate III. 2 a (wings, s and ? , head, s , 3 views, legs, c^ , 

 and forceps, tip of a forceps-limb and penis). Nt/atph, PI. XXVI. (whole figure and 

 details). 

 [Nameless^, Costa, Fn. di Aspromonte, pi. i. 2. 



Oligoneuria % anomala (part), Pict., Nat. Hist. Nevropt. ii. EpLem. pi. xlvi. (143-5) ; Kirsclib., Jahresb. 

 Vereins f. Naturk. Nassau, Heft ix. 44-5 (1853). 0. rhenana, Imh., Bericht iiber Verhandl. d. naturf. 

 Gesellscb. Basel, x. 177-180 (1852); Hag., Stet. ent. Zeit. xvi. 267, pi. i. (1855) ; Brau., Neur. Aust. 25. 

 (1857) ; Rogenhofer, Verb, zool.-bot. Ver. Wien, vii. 130 (1857) ; Mtil., Ent. Mo. Mag. i. 262 (1865), 

 and ii. 182 (1866); Etu., op. cit. v. 83 (1868), and Trans. Ent. Soc. London (1871), p. 55, pis. i. 2, 

 and iii. 7-7 a- Hag., o/j. cit. (1873), p. 390-1 ; Meyer-Diir, Bull. Soc. Ent. Suisse, iv. 307 (1874); trans- 

 lation of Imboff, 1852, by Joly, Bull. Soc. d'Etud. Sc. Angers, Ann. 4-5™f, pp. 37-4-0 (1876). O. pal- 

 lida {0. rhenana, var.?), ! Hag., Stet. ent. Zeit. xvi. 268, pi. i. (1855); ! Etn., Trans. Ent. Soc. London 

 (1871), p. 56. Nymph. — 0. Gurumnica,\ Joly, Zoologist (1873, Aug.) 36555-7, figs, a, b; idem, I'roc. 

 Ent. Soc. London (1873), p. xx. figs, a, b ; ditto. Bull. Soc. d'Etud. &c. Angers, pp. 37-9 & 46, figs, a, b 

 (1876); ditto, Rev. d. Sc. Nat. Montpellier, r. 9 (1876, Dec); ditto. Bull. Soc. d'Et. des Sc. Nat. 

 Nimes, Ann. 6*, no. 4 (separate pgs. 8), figs, a, b [inferior to tbe earlier figures] (1878, April) ; idem, 

 Compt. Rend. Soc. d'Et. des Sc. Nat. Nimes, 1878, pp. 64-9; Vayssiere !, Ann. Sc. Nat. (6) Zool. xiii. 

 54, figs. 52, 58-65 [whole figure and details] (1882). O. rhenana, \ Mill., Mittb. scbweiz. ent. 

 Gesellseb. v. 384-6 (1878). 



Suhimago. — Body much browner than that of the adult fly. 



Imago, living, c? . — Head and thorax brown-ochreoiis, eyes black. Abdomen white, the 

 segments pellucid in their basal halves and opaque behind, their distal dorsal borders 

 narrowly edged with greyish ; in the dried insect the opaque portions of the segments 

 become lutesceut or ochreous ; in the 9th ventral segment (prior to their extrusion) are 

 visible through the integument the light yellowish chitinous mandibuliform appendages 

 to the penis. Setoe and forceps white. Fore legs from the coxa to the base of the 

 femur whitish, and from thence sepia-brown ; hinder legs white, with yellowish white 

 femora and dark ungues : when dried, the fore legs and hinder femora become light 

 yellowish brown. Wings greyish with opaque neuration, the stronger nervures sepia - 

 grev. 



$ . Abdomen previous to the extrusion of the eggs bistre-brown, and opaque when 

 dried, afterwards very light brownish-ochreous ; eggs lutescent. Thorax brown-ochreous, 

 head rather browner in front, leers when dried licyht bistre-brown or brown-ochreous. 

 Length of body, d 9-13, 2 12-15 ; Aving, ^ 11-14<, $ 11-16 ; setai, 6 im. 12-13, subim. 

 (slough) 4; 2 im. 3-4, subim. 25-3 mm. 



Hab. The Rhine, Cologne to Basel ; the mill-stream at Versoix, Geneva ; France, 

 Brive (Haute Loire), Toulouse (Haute Garonne), and Taraseon (Arifege) ; Portugal, 



