EEV. A. E. EATON ON RECENT EPHEMERID.^ OR MATELIES. 83 



each unlike the other ; basal joint of forceps-limb 

 longer than the remainder; egg-valve 



strongly developed; ? ventral lobe of segment 9 bifid and excised . Hagenulus. 

 absent ; $ ventral lobe of segment 9 



obtuse or slightly emarginate ; of the interealaries in the anal- 

 axillar interspace of the fore iving, the nearest to the anal 



out of 4 or 5 is long Thraulus. 



bifid and acutely excised ; of the interealaries quoted, the 



nearest out of 4 to the anal nervure is short Calliarcys. 



about as long as the remainder; egg-valve absent; ? ventral lobe of 

 segment 9 bifid and excised ; of the interealaries quoted, the nearest 



to the anal out of 3, 4, or 5 is short Habrophlebia. 



very short; joint 2 longer than the remainder; 2 ventral lobe of seg- 

 ment 9 obtuse Choroterpes. 



ATALOPHLEBIA, Etn. 1881. 



Ilh(strations. Adult (details), PI. X. 16«-16 h ; (whole figures) see citation of Pictet 

 under A. anstralasica. \_N.B. A median seta is commonly present.] 



Adult. — Hind Aving in front somewhat arched, the summit of the arch ohtusely sub- 

 angular, situated usually before the middle of the curve; subcosta (2) strongly arched, 

 meeting the margin very obliquely ; radius (3) usually nearly straight, constituting as it 

 were the chord of the arch described jointly by the subcosta and the portion of the 

 margin included between its extremity and the radius ; hence, while the narrow marginal 

 area is broadest at the base and acuminate at its termination, the submarginal area is 

 broadest either in the middle, or a little before the middle, and tapers gradually to its 

 oblique apex. Cross veinlets abundant in the fore wing, those in the marginal area 

 before the bulla well defined. At the terminal margin the longitudinal nervures are 

 provided with curved simple branchlets, and there are no isolated veinlets. The two 

 intercalar nervures of the anal-axillar interspace of the fore wing have simple branchlets, 

 and usually the hinder one, close to its proximal extremity, curves forwards to unite with 

 the other, whicli similarly curves forwards to join the anal nervure (PL X. IG c) ; occa- 

 sionally, especially in female specimens, a cross veinlet is trausfei-red from near the 

 wing-roots to establish communication between the first axillary and the anterior inter- 

 calated nervure (/. c. 16 d) ; less frequently, this last nervure annexes itself to the first 

 axillary [l. c. IC e). The figure 16 i exhibits a further departure from the normal neura- 

 tion (supposing the insect to belong to this genus). In A. cmnnlata from Ceylon, the 

 two intercalated nervures referred to are abrupt and free at their proximal extremities as 

 a rule (/. c. 16 a), but individual " sports " occur in which the anterior nervure imper- 

 ferfectly establishes direct communication wdth the anal nervure. Guard at the orifice 

 of the mesothoracic spiracle small and triangular. Porceps-limbs of 6 3-jointed ; the 

 proximal joint much longer than the remainder, somewhat compressed, and in its basal 

 half broadly dilated beneath ; the deflexible basis, usually prominent in the middle of its 

 distal border, is otherwise merely emarginate; the corresponding lobe in 2 , usually bifid 

 and sharply excised witli acute triangular points, is seldom emarginate only. Segments 



