KEY. A. E. EA.TON ON EECENT EPHEMERID.^ OR MAYFLIES. 79 



uniform ; their divisions subequal, plumose or pinnatisect with linear acuminate seg- 

 ments, and not conduplieate lengthwise. SetaB plumose, about i as long as the body. 

 Outer surface of each mandible armed with a single acute spine or tubercle, not prolonged 

 into a tusk ; their innermost fang furnished with a moveable appendage [endopodite]. 

 Lacinia of the 1st maxilla crowned with a patch of dense hair. Median lobe of the 

 tongue obcordate. Antennae setaceous, almost glabrous. Labrum externally strigose. 

 Lobes of the labium very small. Pronotum oblong, nearly straight at the sides, and 

 slightly concave at the margin in front and behind. Intermediate leg the longest. 



Type. P. lutens (in Ephemera), Linn. 



Distribution. Temperate and southern Europe ; also (undescribcd sp.) in the State of 

 Virginia. 



Etymology, ttoto^iuc and avOog, river-flower. 



PoTAMANTHUS LUTEUS, Linn. Plate IX. 14 (wings, legs s 2 , head, penis, and forceps 

 d adult). 



[Epliemera] or Ephemera hitea [Geof., Hist. Ab. Ins. Paris, ii. 238, no. 2] (1764); Linn., S. N. ed. 

 xii. 906 (1767); Fab., Syst. Ent. 303 (1775) ; [? Schaef., Ic. i. pi. xlii. 7 (1776)] ; Schr., En. Ins. Aust. 

 603 (1781) ; Fab., Sp. Ins. i. 383 (1782), and Mant. Ins. i. 243 (1787) ; Vill., C. Linn. Ent. iii, 17 (1789) ; 

 Roem., Gen. Ins. 23 (reproduced from Scliaef. 1776) ; [Zsch., Mus. Lesk. i. 50, no. 14] (1789) ; Gmel., 

 Linn. S. N. ed. xiii. p. 2628 ( 1790) ; Ros., Fn. Etr. ii. 8 (1790) ; 01., Encyel. Method, vi. 417 (1791) ; Fisch., 

 Vers. ein. Naturgesch. v. Livland, 565 (1791); Fab., Ent. Syst. emend, iii. pars i. 68 (1793) ; Seetzen, 

 Meyer Mag. f. d. Thiergesch. i. 41-63 [Hag.] (1794); Schr., Fn. Boica, Heft ii. Bd. ii. 197 (1798); 

 Walck., Fn. Paris, ii. 8 (1802) ; Lat., Hist. Nat. xiii. 95 (1805) ; Blanch., Hist. Nat. Ins. iii. 54 (1840) ; 

 Duf., Mem. par div. sav. Instit. de France, viii. 580, note ( 1841) ; [Joly, Feuil. d. jeun. Nat. 1876, Mars, 

 pi. ii. 6 (legs misdrawn)]. — ? E. J marginata, Miil., Zool. Dan. Prod. 142 (1776).^ — E. reticulata, 

 Fourc, Ent. Paris, ii. 350 (1785). — E. hyalhia, Pz., Explic. Schaef. Ic. xliii. (1804).^^. flavicans, 

 ! Ramb., Nevropt. 296 (1842) ; Walk., List of Nenropt. Ins. in Brit. Miis., part iii. 536, ? var. (1853).— 

 E. chlorotica, ! Ramb., Nevropt. 296 (1842) ; Walk., op. cit. 540 (1853). 



%Baetis mellea, Curt., Phil. Mag. ser. 3 (1834), p. 121. — jB. marginalis, Burm., Handb. Ent. Bd. ii. 

 Abth. ii. 801 (1839). 



Potamanthus luteiis, Pict., Hist. Nat. ii. Ephe'm. Nevropt. 208, pi. xxv. 2, 3 (1843-5); Walk., List of 

 Neuropt. Ins. in Brit. Mus. part iii. 539 (1853) ; Hag., Stet. ent. Zeit. xxvi. 229 (1865) ; Etu., Trans. Ent. 

 Soc. London, 1871, p. 76, pi. ii. 1 (wing), and iv. 13-13 « [details] (1871) ; Meyer-Diir, Bull. Sec. Ent. 

 Suisse, iv. 317 (1874) ; Rostock, Jahresber. d. Ver. f. Naturk. Zwickau, 1877, p. 83 (1878); M'Lacn., 

 Ent. Mo. Mag. xv. 92 (1878). 



Eucharidis Reaumuri, ! N. & E. Joly, Rev. d. Sc. Nat. Montpellier, v. 314, pis. vi. 13-15, vii. 16, and 

 viii. 30, 31 [nymph] (1876). 



Suhimago {living). — Wings yellow, or in the ? tinged with greenish grey ; the fore 

 wings rather darker towards the costa, with black cross veinlets. Eyes of 6 light olive- 

 green (flavo-virens, Miiller), or sometimes light grass-green (gramineus. Mill.). From 

 head to tail a broad median brownish yellow-ochreous stripe occupies most of the 

 dorsum; this is narrowed towards the base of every abdominal segment, and contains 

 the usual pale pair of short divergent lines and dots in each of them : the remainder of 

 the body is sulphur- or straw-yellow, but in the abdomen near the bases of segments 2-9, 

 close to the spiracular line, is a black dot on each side of the dorsum, and higher up in 



11* 



