It is described in Ray's " Historia Insectorium," 1710; and Petiver, in 

 1717, wrote "I have observed this in Hampstead and other woods in June. 



Genus VI. GONEPTEREX. 

 Leach. 



Gonepterex. Gonos, angular j Pteris, a wing. 



This is also a small genus, possessing a little over a dozen species, only 

 two of which, Rhamni and Cleopatra, occur in Europe. A distinguishing 

 feature is that the body, which is rather stout, is covered with long silky 

 down. All the wings possess an angular projection. The antennae are short, 

 rather thick, and of a red colour, hence Boisduval named the genus Rhodocera. 



GONEPTEREX RHAMNI. 

 Brimstone Butterfly, 



Rhamni, Linn. Rham'ni, from Rhamnus the generic name of its food- 

 plants, the Buckthorns. 



The general colour of the male is a clear brilliant yellow, much like that 

 of the Daffodil, its contemporary ; and in the centre of each wing is a small 

 spot of rich orange. As the male, from his colour, bears the name of "Brim- 

 stone " or " Sulphur," so the colour of his consort may be accurately com- 

 pared to the tint of another chemical preparation, called " Milk of Sulphur." 

 On the wing she is often mistaken for the Large Cabbage White. The 

 expanse of the wiugs varies from two inches four lines to two inches and six 

 lines. 



Yar. b. Male with the wings clouded, and minutely dotted and streaked 



with orange. 



Var. c. Male with an orange patch on the fore-wings, somewhat resembling 



Cleopatra. 



The egg is laid singly, generally on a rib of the under side of a buckthorn 

 leaf in April or May. At first it is of a silvery-green, but afterwards turns 

 to a yellow. In shape it is cylindrical, and resembles a flask. 



The caterpillar, which feeds on buckthorn and blackthorn, and also, accord- 

 ing to Lewin, on the wild rose, in June and the fore part of July, is of a dull 

 green colour, and has a white lateral streak. It is subject to the attack of 

 an hymenopterous parasite — Limneria vulgaris, which, according to Mr. 

 Bignell, forms its cocoon inside of the caterpillar, and so constructs it, that 

 the skin of the caterpillar is made to do duty for an extra protection. 



