SYNOPSIS OF THE BRITISH EPHEMERID.E. 11 



dark pitchy-brown ; antennal bristle and caudal fila- 

 ments grey ; legs pale-brown ; anterior legs grey ; 

 Avings transparent milky-white ; the two costal ner- 

 vures black-brown, the basal half darkest. The 

 colouring of the female is only a little paler -, caudal 

 filaments white, feathered for some distance, the base 

 rather darker. 

 Length of the body IJ lines; expansion of the wings 



4^ lines; setae ^ 7 lines, ? H lines. 

 Habitat near London, in June. 

 The description is made from a pair communicated to me 

 by Mr. "Walker. Stephens says, "filaments faintly dotted 

 with fuscous," which probably only arises from the darker 

 parts of the joints. Probably this is identical with C, luc- 

 tiiosa, Burmeister, Pictet; but my specimens from Nice are 

 rather smaller, and show distinctly the black spot at the 

 tarsal joints mentioned by Pictet ; this scarcely appears to 

 be represented in the English specmiens. 



2. C. HALTERATA, F. ; C. gi'isea, Pict. ; C. chironoforinis, 

 Steph. 62, 6, ? imago ; Curtis, Phil. Mag. 122, 2. 



Imago. Head and thorax shining pale-brown ; antennae 

 grey, the base darker ; the antennae of the female quite 

 dark-grey ; mesothorax anteriorly gently sloping ; ab- 

 domen beneath yellowish, above brown-grey, with 

 indistinct black transverse streaks from the stio^ma : 

 legs white, the anterior legs greyish ; anterior femora 

 of the male dark grey, blackish at the joint, tibiae and 

 tarsi snow-white, with the tips rather darker; caudal 

 filaments white. Wings hyaline ; the two costal ner- 

 vures black-brown nearly to the apex. 



Length of the body $ 1|, ? 2j lines ; expansion of 

 the wings $ 4|, ? 5f lines; setae $ 7A, ? 2 J lines. 



