176 KEV. A. E. EATON ON EECENT EPHEMERID.¥. OR MAYFLIES, 



in Hudson's Bay Ter. [probably St. Martin's Ealls, Albany river]. This species is abun- 

 dant in Great Britain, and reaches maturity in the southern counties from April to 

 November. It is found in Germany, Switzerland, and Erance (at Dijon, M'^Lach.), in 

 addition to the countries quoted above : it is common at Pallanza along the shore of the 

 Lago Maggiore (640 ft.), and near Cintra in the valley N. of the town (385 ft.). The 

 acute projecting point noticeable above the forceps [the limbs of which are nearly con- 

 tiguous at the base], and tlie sharpness of the hind wing are preeminently distinctive of 

 C. luteolum. The terminal joints of the forceps-limbs are straight. Female specimens 

 are sometimes distinguishable from Clo'eon rufulum only by their possessing hind wings. 



Centeoptilijm lactjstre, sp. nov. 



Imago {living). — d . Very similar to C. 2^efinulatum,\>vX with the turbinate eyes red, 

 and with the tips of the transparent abdominal segments less strongly coloured. 



? . Eyes light olive-grey. Body light brownish ochre ; this colouring in segments 

 2-6 of the dorsum is restricted to a median triangle projecting forwards from the hinder 

 border of each segment, leaving the remaining parts pale ; their subcutaneous tracheae 

 are dark ; segments 7-10 viniformly light broMuish ochre ; venter pale. Setae white. 

 Legs nearly colourless, but faintly tinged with yellowish at the tips of the femora. Wings 

 vitreous ; the pterostigniatic portion of the marginal area of the fore wing contains 6-9 

 simj)le cross veinlets. Length of body 5"5-6 ; wing 6-7 ; setae, <s im. 12-14, 2 im. 

 about ]0 mm. 



Hah. Pallanza on Lago Maggiore (640 ft.) ; at the lake side, about sunset on the 18tli 

 July. The forcejis and bind wing are very like those of C. pennulatmn. 



Centroptilum penntjlattjm, Etn. PL XVII. 30 i ( c? , head, legs, hind wings and forceps). 



Ceniroptilumpennulatum,\'Ein.,'VYans. 'Eni. Soc. London (1870) 2; \id., op. cit. (1871) 139. pi. v. 

 14, 14 a ; Rostock, Jaliresb. d. Ver. f. Naturk. Zwickau, 1877, p. 85 (1878). 



Suhimago. — Wings a very little greyer than those of C. Inteolam : distinguishable from 

 that species chiefly by its greater stature. 



Imago {living).— d . Turbinate eyes light cadmium-orange ; lower eyes olive-grey or 

 black. Prouotum dusky, or light luteo-fuscous ; meso- and metanotum either light 

 luteo-fuscous, raw sienna, or bistre-brown. Eirst dorsal segment of the abdomen pioeo- 

 fuscous ; segments 2-6 vitreous, tinged at the joinings very faintly with Mars-orange; 

 secments 7-10 reddish brown-ochre or reddish chestnut-brown, modified with Chinese- 

 orange above, but ochraceous white beneath. Setge and forccjos white. Legs white, with 

 the tips of the femora yellowish white, and with the terminal tarsal joints faintly tinged 

 with very light sepia-grey. 



2 . Eyes olive-grey, or greenish black ; vertex of head light yellow, with a broad 

 median burnt-sienna stripe from the anterior ocellus to the occiput, and with the orbits 

 of the ocelli black. Notum light dull brownish ochre modified with bistre-grey. Abdo- 

 men in dorsal segments 2-6 bistre-grey, in 7-10 reddish brown-ochre, with the usual 

 abbreviated median line and two short divergent pale lines in segments 2-8, with 

 the tips of segments 2-7 either brown-ochreous modified more or less with Mars-orange, 

 or deep reddish brown, or narrowly piceous, and with streaks of the same colour pro- 



