THE SWISS SPECIES OF THH GENUS HESPERIA. AT 
the species themselves. In the first vol. of Seitz’ Macrolepidoptera of 
the World all the palearctic black and white “skippers” are massed in 
the genus Hesperia. The reason for this ‘lumping ”’ matters little ; 
but it is interesting to note that to treat this swarm of species in an 
intelligible fashion, Mabille had to divide them into sections and sub- 
sections, more or less corresponding to the specialised genera in which 
the species have been placed by modern writers. ‘Thus we find the 
restricted genus Hesperia approximately represented by section ‘ C,” 
divided into two sub-sections: (a) Those species. having the ‘‘ white 
discocellular spot of the hindwing beneath straight and without a 
projection towards the base,” and (b) those species having the ‘“‘ white 
discocellular spot on the underside of the hindwing prolonged towards 
the base.” The species of the genus fall naturally into these two 
groups, and, it is safe to say, that if, in the past, writers had always 
so divided the genus, much of the confusion which has so long 
enveloped it would have been avoided. The characteristic features of 
these two groups have been noted by many authors, but only as 
applicable to individual species. I have therefore, in the following 
notes, placed the species in their respective groups, “‘ A” and “ B,” as 
designated by Mabille, hoping that I may help to bring them into more 
general use, and so demonstrate their practical value. The majority 
of collectors will appreciate the fact that by identifying the group to 
which their specimen belongs, they are reducing by half the difficulty 
of naming it. Further, if it is desired to make any detailed study of 
the variation of the species of the genus, it is absolutely necessary to 
familiarize oneself with the characteristics of each of these groups, as 
one of the most important lines of variation is that in which the 
features of one group are assumed by an individual of a species 
belonging to the other. This division of the species, apple! to the 
Bharopen n species, gives one the following results :— 
I. Those species in which the inner edge of the median band 
underside hindwing is rectilinear, the central spot not 
projecting towards the base of the wing=group A, and 
includes : 
alveus, vryjfelensis, armoricanus, belliert, carlinae, fritillum, 
serratulae, cynarae, and melotis. , 
“II. Those species in which the inner edge of the median band 
underside hindwing is not rectilinear, the central spot pro- 
jecting sharply towards the base of the wing=group B, and 
includes : 
carthami, andromedae, centaureae,, cacaliae, onopordi,  sidae, 
malvae, and eineiiee 
The position of melotis is, perhaps, doubtful. Mabille places it in 
group A, and in M. Culot’s excellent figures (Bull. Soe. Lep. de Gen.) 
such remnants of the median band as are visible seem to justify his 
doing so. 
Group A. 
H. alveus, Hb. 
Alveus is one of the most interesting species of the genus, owing 
to the fact that it is so prolific in local races. Many of these so-called 
races have turned out to be distinct species, and probably in the future 
more of them will be found to be so too. In very few instances, how- 
