18 BRITISH BUTTERFLIES 
varieties of C. Edusa*. The figures indeed given of C. Chrysotheme, especially those of Boisduval (Icon. Hist. 
des Lépidopt. pl. 9, fig. 3, 4) differ materially from those of Stephens ; and as C. Chrysotheme is described as « 
native of Hungary, Syria, and Southern Russia, it is most probable that that species is not a native of England. 
Boisduyal has indeed noticed a character which will satisfactorily decide the specific identity of the English 
specimens with C. Chrysotheme or C. Edusa, the genus being divisible into two groups, C. Edusa belonging to 
the first, in which the males are provided with a glandular space or sac at the anterior edge of the hind wings 
near the base, whilst in the second group, to which C. Chrysotheme belongs, they are destitute of this sac. 
The following is a translation of Boisduval’s description of the true C. Chrysotheme, which I have here 
introduced in order that it may be compared with Mr. Stephens’s description of the supposed English species :— 
“Figure of C. Edusa, but about one fourth smaller. Upper side of the wings of a paler yellow, with the 
margin browner, divided in the fore wings by fine yellow nerves; the fore wings having moreover the costa 
broadly yellow. The discoidal spot is narrower, transverse, slightly marked, and edged with a little red. The 
under side of the fore wings nearly as in C. Edusa and the allied species, except that the discoidal spot of the 
fore wings has the centre rather pupilled with silver. The female is much paler than the female of C. Edusa, and 
the yellow orange colour only occupies the disk of the fore wings, and the yellow spots which divide the dark 
margin are larger, more marked, and of a much paler yellow colour.” 
The generic name Colias appears to have inappropriately derived by Fabricius from xoA‘as, a word used by ' 
the Greeks for some kind of fish. 
Mr. Stephens gives Norfolk or Epping Forest as the locality of one of his British specimens. 

GENUS V. 
PIERISt+, Scuranx. PONTIA, Srepuens, &c. 
In its present restricted state this genus consists of species, which from their common occurrence in our 
gardens throughout the summer, have attracted our earliest attention ; their almost uniform white colour, and 
the places where they mostly frequent, having led to their receiving the ordinary name of Garden Whites. From 
the preceding genus they are distinguished by the more acute tip of the fore-wings, and by their longer and 
slenderer antennze, which are terminated by a broad compressed and obtuse club. The palpi are short, three- 
jointed, nearly cylindrical, with the terminal joint as long as or rather longer than the second. The legs are long, 
slender, and alike in both sexes, the anterior pair being perfect. 
The tarsi are terminated by two equal-sized hooklets much curved, each having a small tooth on its under 
side ; between these hooklets is a long fleshy pulvillus, and each is laterally defended by a long conical hirsute 
appendage. The details of this curious structure are represented in the Crochard edition of the Régne Animal, 

* It is to be observed that M. Boisduval describes no other variety of C. Edusa than the C. Helice. Can the small English specimens 
be C. Myrmidone ? 
+ Derived from Mepts, plural Mepides, the Muses, a poetical licence similar to that used in giving the name Parnassus to the genus having 
P, Apollo for its type. 
