EEV. A. E. EATON ON EECENT EPJrEMERID.E OR MAYFLIES. 193 



paler and yellowish ; the abdomen discoloured, but rather uniformly coloured and orna- 

 mented throughout ; its integument densely, minutely, and irregularly rugulose on the 

 back, and foveolate ventrally ; setre white with black joinings (but these are reddish in 

 imperfectly developed seta>). Wings vitreous, brilliantly iridescent ; the fore wing 

 ornamented with piceous, broadly along the costa, very narrowly along the terminal 

 margin, and very variously in the disk ; the costal markings may be described as a 

 longitudinal stripe, deeply and ii^regularly eroded posteriorly, and varied diversely in 

 different specimens with pellucid spots enclosing the cross veinlets ; the terminal margin 

 is white or jiellucid at the terminations of the longitudinal nervures, but elsewhere pitch- 

 brown, and the interneural veinlets arising from it are similarly dark, and sometimes are 

 enveloped in little nebula? of the same colour, or spots ; the irregular spots of the disk are 

 in connection with dark portions of the longitudinal nervures ; these are mostly white, 

 banded with piceous, only tjie costa, subcosta, and radius being piceous throughout ; cross 

 veinlets opaque white ; the marginal area contains about 8 cross veinlets before, and 13 

 within the pterostigmatic space, mostly simple, though a few are forked. Femora fusco- 

 lutescent, minutely and densely punctulate with darker, especially towards their distal 

 extremities; tibiae slightly paler, darkened at their distal joinings; basal joint of the 

 tarsus almost concolorous with the tibia, but the extremity of the tibia, together with 

 the rest of the tarsus, is dull black. Length of body, $ 12; wing 12; setae about 

 17 mm. 



Hal). Puget Sound and other parts of Washington Territory (Ilag. and M'Lach. Mus.) 

 and California (M^Lach. Mus.). 



Callib^tis feR-RUGINEUS, AYalsh. Plate XVI. 28 b (wings 2 im.). 



Cloe X iindata, ! Hag., Smithson. Miscell. Coll. (1861), Synopt. Neuropt. N. Atn. 53 [part] .— C./e;-- 

 ruginea, Walsh, Proc. Acad. Nat. Sc. Philad. (1862), ZTd.—C. fluctuans, id., loc. cit. (1862); Hag.,Proc. 

 Ent. Soc. Philad. ii. 178 (1863). 



Baatis fluctuans, Etn., Trans. Ent. Soc. Loudon (1871), V22.—B. (?) undatus, id., op. cit. (1871), 123 

 [part] ; Hag., op. cit. (1873), 402 [part]. — B. ferrugineus, Etti., op. cit. (1871), 121 ; Hag. & Etn., op. 

 cit. (1873), 402 [part]. 



Subimago (dried). — Wing-membrane sepia- or bistre-grey ; cross veinlets white, narrowly 

 bordered with transparency in a manner very similar to those of C. Hageiii ; longitudinal 

 neuration for the most part pale and similarly edged with transparency, the costa, sub- 

 costa, and radius of the fore wing (and, in parts, some of the other nervures) darkened 

 uniformly with the ground-colour of the membrane. Legs sublutescent ; the apical 

 borders of the first three tarsal joints, and the extremity or sometimes the whole of the 

 terminal joint, also the fore tibia, brown. Setae pale sepia-grey, their joinings either 

 )paque or blackened. 



Imago (dried). — Wings colourless in the 6 , ornate in the 2 ; femora usually quite 

 'ree from dots, and then normally pale lutescent in both sexes ; or in the <^ Avhitish, but 

 douded with pale lutescent before their extremities ; sometimes in the c? they are dotted 

 ninutely in part or throughout ; tarsi of the d in great measure white. — 6 . Thorax 

 lormally piceous or fusco-piceous ; abdomen normally with the dorsum uniformly rufo- 



SECOND SERIES. — ZOOLOGY, VOL. III. 2G 



