1863.] 
357 
with euproiiychia. Claws but little curved, deeply bifid, and without 
paronychia or pulvilli. 
I have separated three species, 
C. Cse,mnia^ Stoll. 
C. eurijdice^ Boisd. 
C. Philippa? Fab. 
together with one about to be described, from the genus Colias, with 
which they have been heretofore associated, but from which they are 
widely distinct, with the purpose of forming a new group, correspond¬ 
ing with the above diagnosis. They differ in the shape of the wings 
and in their nervular system, but chiefly in the possession of peculiar 
appendages, found on the middle and posterior legs of the female, and 
to which I have given the name, eupronychia. 
They are to be found on the under side of the tarsi respectively at 
two-thirds, and three-fourths of their length, as two small membranous 
appendages, each being tri-jointed. The first joint is at the point of 
insertion into the tarsus; at the second, some distance below, both be¬ 
come bifid, when each branch, after being again jointed, curves ab¬ 
ruptly upward, dilating into a semi-transparent, oblong, irregular, 
pyriform disk, becoming lateral to the tarsus, and extending in the 
upper and longest pair, beyond the insertion of the lower, which in 
their turn, are carried beyond the ungues. 
These can be referred neither to paronychia, which are placed above 
the claws, nor to pulvilli, between them. The measurements of the 
different sections are given below, and may prove interesting to the 
investigator; they are expressed both in inches and millimetres : 
First pair or upper eupronychia— 
A. Length from the insertion or 1st joint to the 2nd.81199 in.....03020 mill. 
B. of the branches from the 2d to the 3d joint...01411 in.03558 “ 
C. of the pyriform disks. ....03746 in.....09515 
Total length. 06356 in.16093 
Second pair or lower eupronychia— 
A. Length from the insertion of 1st joint to the 2nH........00796 in.02019 mill. 
B. ‘‘ of the branches from the 2d to the 3d joint...01965 in.....02705 “ 
C “ of the j)yriform disks.04167 in.10584 
Total length.06027 in.15308 
