108 EEV A. E. EATON ON EECENT EPHEMERID^ OR MAYFLIES. 



morning (8-10 a.m.) before the sea-breeze arose. The only specimens of the adult and 

 subimago obtained were struggling in a spider's web. 



Thraulus signatus, Hag. 



Cloe signata, ! Hag., Verh. zool.-bot. Gesells. Wien, viii. 477 (1858), & ix. 206 (1859) ; [Gen. ?], 



Etn., Trans. Ent. Soc. London (1871), 131, note. 



Leptophlebia (Etn.) signata, Hag., op. cit. (1873), 395. 



Subimago (dried). — Wings talcose, transparent, dark sepia-grey, with concolorous 

 neuration. Seta? of a Hke colour, with dark joinings. Thorax dull pitch-brown ; legs of 

 duller colour than those of the imago. 



Imago {dried). — s . Thorax polished, bright pitch-brown or rufo-piceous ; dorsum of 

 abdomen purplish sepia-brown ; segments 2-6 translucent, paler at the base and sides, 

 but opaque at the joinings, and blackish at the stigmata; venter subochraceous with 

 darker joinings, excepting the ninth joint and the inwardly dilated base of the forceps, 

 which are somewhat rubiginose ; setse light sepia-grey, with blackish joinings. Wings 

 transparent colourless, iridescent ; their longitudinal nervures translucent, very faintly 

 tinged with pale brownish or amber colour, the wing-roots piceous ; about 5 simple 

 nearly straight cross veinlets in the pterostigmatic space of the fore wing. Fore legs 

 lost ; femora and tibiae of the hinder legs the palest Vandyke-grey, the former banded in 

 the middle and at its extremity with black, the tarsus and ungues faintly tinged with 

 testaceous. 



? very similar but darker ; the ventral joinings of the abdomen more widely opaque; 

 the pterostigmatic space of the fore wing sometimes contains 7 simple nearly straight 

 cross veinlets. Length of body 5 ; wing, d 6, ? 7 ; setge, 6 and 2 im. about 6 mm. 



Mab. Rainbodde, Ceylon, at altitudes of upwards of 4000 feet (Hag. Mus.). I do not 

 think that the dilated portion of the base of the forceps is a separate joint. 



With the types of Thraulus signatus stood single examples of two other species, perhaps 

 of the same genus, from the same locality, numbered respectively 32 and 37. 



Compared with Thratdus signakis, no. 32 presents the following differences : — none of 

 the femora have a median black band, but only the terminal band ; the dimensions of the 

 insects in length of wing and body being the same, the legs of 82 are proportionally 

 longer, and their colour generally is more flavescent ; the wings have a stronger neura- 

 tion, the longitudinal nervures are distinctly browner ; in the pterostigmatic space are 

 10 simple and straight cross veinlets, of which the four nearest to the bulla are very 

 faint. 



No. 37 has the binder legs uniformly pallid (fore legs lost), and 5 simple straight, or 

 nearly straight, cross veinlets in the pterostigmatic space liner than those of Th. 

 signatus. 



Theaulus exigutjs, sp. nov. Plate XIII. 20*" (forceps, penis, wings, and hinder foot). 



Imago {dried), s . — Thorax above luteo-piceous. Abdomen discoloured, fuscescent. 

 Hinder legs whitish, with femora banded very broadly with black in the middle, the 

 extremities of the femora and bases of the tibiae also blackish, and the tarsi somewhat 



