140 EEV. A. E. EATON ON EECENT EPHEMERID.E OR MAYFLIES. 



of body, S (eggs discharged, and therefore shruuken) about 5'7 ; wing 10 ; setae about 

 8-9 mm. 



Hab. Cape of Good Hope (Burm.j. Described from a specimen in Dr. Hagen's collec- 

 tion (Winthem). The comparative elongation of the wings noticed by Dr. Hagen (1873) 

 is doubtless due to the sex of this example. 



Tricorythtjs (?) sp. (nymph). PL XLI. (whole figure and details). 



Ctenis or C(Enis maxima, Joly, Bull. Soc. Hist. Nat. Toulouse, iv. 144, pi. ■ — ? (1870) ; id. Rev. d. Soc. 

 Savants, ser. 2, iii. G9-72 (1873) ; id. Feuil. d. jeun. Nat. ann. 6, 53-4, pi. ii. 7 (1876) ; ! Etn., Ent. 

 Mo. Mag. xvii. 190 (1881). 



Tricorythus, ! Vayssierc, Arm. d. Sc. Nat. 6" s6v. Zool. xi. 3, 4, pi. i. 1 (1881) ; id., op. cit. xiii. 65, 

 pis. vi. 54, viii. 81-90 bis, & ix. 94-97 (whole figure aud details). 



Adult unknown. 



Nymph of mature age ; length of body 10, outer setae 7 mm. 



Hab. The Garonne near Toulouse (Dr. E. Joly). I am disposed to suspect that this 

 nymph has been too hastily referred to Tncorytlius ; the adult may be of a genus at 

 present unknown ; but I could not distinguish the neuration of the wings satisfactorily 

 in the nymph, and therefore this is only a conjecture. 



LEPTOHYPHES, Etn. 1882. 



Illustrations. Adult (detail), PI. XV. 25 bis. 



Adult, ? . — 'Uind wings absent. Caudal setae 2, about as long as the wings. Cross 

 veinlets multiserial, numerous in the larger portion of the wing, but absent from the 

 marginal area and from the vicinage of the terminal and inner margins ; these are devoid 

 of isolated rudiments of veinlets and perhaps of fringes, and the longitudinal nervures 

 have no brauchlets at their terminations. The anal-axillar interspace contains two well- 

 develojied intercalar nervures, each of which, like the 1st axillar (9^), is met at its anterior 

 extremity by two cross veinlets, — one from each of the nearest adjacent nervures ; the 

 anterior of these intercalars is a little the larger, nearly straight, and is connected by 

 several obsolescent cross veinlets with the anal (8) nervure, to which it is subparallel ; 

 the hinder intercalar is almost imperceptibly curved, nearly bisects the area intervenient 

 between the first intercalar and the first axillar nervures, and is connected more strongly 

 with the former of these than with the latter. The recurrent membrane of the wing- 

 roots projects as a subulate point beyond the peak of the scutellum. Other particulars 

 unascertained. <s unknown. 



Type. L. exlmius, Etn. 



Distribution. Argentine Republic. 



Etymology. XeTTTow^/jc, finely woven ; referring to the tenuity and relative abundance 

 of cross veinlets. 



Leptohyphes eximius. pi. XV. 25 bis (wiug). 



Leptohijphes ezimius, ! Etn., Ent. Mo. Mag. xviii. 208 (1882, Feb.). 



Adult (dried), $ , — Body discoloured dull pitch-black. Wings talcose, transparent, 



