POLVOMMATUS. 95 



river. It is a double-brooded Butterfly, both in England and 

 on the Continent, and is met with from May to September. 



The Clifden Blue is a little smaller than P. corydon, the 

 largest specimens rarely measuring an inch and a half across 

 the wings. The male is of a brilliant sky-blue above, with 

 narrow black borders, and the fringes white, spotted with black. 

 There is often a sub-marginal row of small black dots on the 

 hind-wings. The female is brown above, more or less blue at the 

 base, and with a row of sub-marginal orange spots, which border 

 the black ones on the hind- wings ; the fringes are black and 

 white, as in the male. There is a black discoidal mark on the 

 fore-wings only. The under side is grey, with discoidal lunules, 

 a row of spots beyond, and a marginal row of orange spots, 

 bordered with black ones. The hind-wings have three basal 

 spots, forming, with the central row of eyes, nearly a circle 

 round the discoidal spot. For the differences between the 

 female and that of P. corydon, see that species (p. 92). 



In the variety P cinnus, the spots of the under side are not 

 ocellated, and in var P. ceronus, the female is blue above, 

 instead of brown The true P. dorylas, of Denis and SchifTer- 

 miiller, with which Stephens confounded a variety of P. 

 thetis, is a European species which does not occur in the 

 north-west ; it resembles P. thetis in the shade of blue in the 

 male, but the fringes are white, and unspotted. Stephens' 

 description of his P. dory las, which is supposed to apply to a 

 variety of P thetis, is as follows : " The male is of a bright 

 blue above, and has a slender black marginal line as in P. 

 adonis, but the cilia are immaculate ; beneath, the anterior 

 wings are pale cinereous, and have a central transverse black 

 streak on the disc, followed by a waved row of black dots 

 faintly cinctured with whitish ; there is then a delicate inter- 

 rupted band of fulvous, terminated with a whitish margin ; 

 the posterior-wings resemble these of P. adonis ; but they are 



