ON THE GENUS PONTIA. 129 



have two black spots ; the under wings are bright yellowish, sprinkled 

 with very minute black points at the base. 



Var. £. — Above, entirely of a light yellowish colour, in some specimens ap- 

 proaching to buff — the black markings as in the typical variety. 



Var. y. — Distinguished from the true rapes, by the spots on the superior wings 

 being very indistinct, and the spots on the tips being paler, with their 

 inner edge less defined. 



Var. t. — Denominated by Stephens, who considers it distinct from P. rapce, 

 P. metra ; differs from the last var. by the spots on the superior wings 

 being entirely obsolete, and the tips are merely shaded by a few dark 

 points. Mr. Stephens imagines that the caterpillar of this variety (I 

 cannot call it species) differs from that of the rapce — i" have reared both 

 varieties from the same cluster of eggs. This I conceive, together with the 

 fact that Var. y. so well connects the typical variety and metra, will 

 settle the matter at once, by proving that the latter cannot rank higher 

 than a variety of the former. Neither do we find that this variety has 

 a different season of appearing from that of P. rapce ; I have taken spe- 

 cimens in June, August, and September, so that it cannot correctly be said 

 to be an early species. In April last year I met with a specimen, but 

 then I took also one of P. rapce. 



The caterpillar of this species is light green, with a pale blue along the 

 back, and a whitish streak, somewhat punctured with yellow on each side 

 of the belly ; feeds on Cabbages, Turnips, &c. 



Sp. 3, Pontia napi. 



Sgn. — Pont. napi. Steph. Haust. — Jard. Brit. Butterflies, pi. 9, fig. 1. — 

 Papilio napi, Linn. — Lewin,j»/. 27. — Donovan, viii. 23, pi. 280, fig. 1.— 

 Green vein'd white, Harris. The Navew, Renn., Consp. p. 3. 



Sp. char. — Easily distinguished from the preceding species by the distinct 

 greenish veins, branching over the disk of the under surface of the wings. 

 Above, the tips of the primary wings dusky, and in the male there is a 

 round black spot in the middle, not very remote from the upper margin ; 

 the female has two such spots on the upper wings. Expanse from 17 to 

 22 lines. 



This species is subject to very considerable variety in its marking : I 

 shall only particularize two varieties, which I think have erroneously been 

 considered as species. There exists a gradual variation of specimens 

 from one variety to the other, which completely connects them. 



Var. /3.— Rather larger than the typical variety. Differs in the veins being dark 



