EEV. A. E. EATON ON EECENT EPHEMEEID.E OE MAYFLIES. 139 



and supports a short lax filiformly dissected appendage, projecting diagonally from tlie 

 point of attachment into the concavitJ^ The other tracheal branchiajare smaller, closely 

 imbricated, decumbent, pergamentose, ovate-triangular, concave beneath, and fringed 

 with crowded, long, unilaterally branched, lax fiilamentose fimbria? ; and [teste Vayssiere] 

 each of them shelters in its concavity a filamentosely dissected appendage. Caudal setae 

 about f as long as the body, rather similar to those of Ephemerella in the quality and 

 disposition of their hairs, but lacking pilosity. Various parts of the body are beset with 

 peculiar hairs resembling those of Ephemerella and Troml)idiid Acarina. Hind leg the 

 longest, the tarsus (claw excluded) about f as long as the tibia ; fore tarsus nearly as 

 long as the fore tibia. Antenna? of moderate length, subulate, almost nude. 



Type. T. varicauda (in denis), Pict. 



Distribution. Upper Egypt and Cape of Good Hope ; also (undescribed sp.) the Malay 

 Archipelago. The nymph described inhabits the south of France. 



Etyniologij, TpiKopvOoc, with triple plume. 



Tricortthus varicauda, KoUar, MS. 



Ephemera [Savigny, Descript. de I'Egypt. Hist. Nat. i. 194 (Explic), ii. Nevropt. pi. ii. G, 7 (1817)]. 



Ccenis varicauda, Pict., Hist. Nat. Nevropt. ii. Ephem. 281, pi. xliii. 5 (1843-5); Walk.^ List of Neuropt. 

 Ins. in Brit. Mu,. part iii. 581 (1853). 



Triconjthus varicauda, Etn., Ent. Mo. Mag. v. 82 (1868) ; id.. Trans. Ent. See. London (1871), 92, pi. ii. 

 3, 3 a [wing, after Savigny] . 



Adult {dried), 3 . — Body" pale yellowish ; eyes and a spot on the frons black. Meso- 

 thorax i*ather darker laterally, with some longitudinal black marks [sutures ?]. The 

 last five segments of the abdomen have each a black dot (" point ") above. Setaj white 

 finely annulated w ith black. Legs yellowish, with some greyish clouds. "Wings and 

 neuration slightly yellowish, except the subcosta and radius (" la costale et la sous- 

 costale "), wdiich are rather darker, without being quite so dark as in Ccenis argentata 

 and C. haUercda. Length of body, d 4, expanse of wings 10, length of seta? 9 mm. 



llab. Upper Egypt. [After Pictet.] 



Tricorythus discolor, Burmeister. 



Oxycypha discolor, Biirm., Handb. d. Ent. Bd. ii. Abtli. ii. 797 (1839). 

 Clo'eon discolor. Walk., List of Neuropt. Ins. in Brit. JIus. part iii. 577 (1853). 



Ccenis discolor, Etn., Trans. Ent. Soe. London (1871), 96; ! Hag., op. cit. (1873), 399 [C. a/iiaTfl, 

 Winthem, MS.] . 



Suhimago {dried), $ .—Head dull dark grey above ; pronotum greyish fuscous, meso- 

 and meta-notum dull lutescent or brown-ochre; dorsum of abdomen dark cinereous, 

 venter and eggs ochraceous ; seta? white, pubescent. Wings throughout very pale sepia- 

 grey, translucent ; longitudinal nervuros subopaque, slightly brownish ; cross veinlets 

 very indistinct ; the darkened appearance of the costal border is due merely to the sub- 

 costa and radius being closed together by shrinkage of the membrane. Legs pale flaves- 

 cent ; the fore-femur edged with fuscous, the tibia and tarsus dark sepia-brown. Length 



