INTRODUCTION. Xvi 
when certain trees are in flower. The Central-American species belong to two 
subfamilies, the Nemeobiinze and the Erycinine, all but three of the genera belonging 
to the latter. 
LYCANIDS. 
Under this head we have placed six genera: Thecla (in the wide sense), including 
upwards of 200 species ; Lycana, which is very poorly represented, as is the case all 
through Tropical America, thirteen species only occurring within our limits: Theorema, 
Lhectopsis, and Chrysophanus, each containing one or two species only, and the latter 
probably not really congeneric with the typical Palearctic and Nearctic forms of that 
genus; and Eumeus, with two species. Theorema and Theclopsis are common to 
Central and South America; Euwmeus extends north and south of our region, and also 
occurs in the Antilles; the insect provisionally referred to Chrysophanus is peculiar to 
Guatemala; Thecla and Lycena are generally distributed. We have already spoken 
of the great diversity amongst the species of Thecla, and it, no doubt, requires sub- 
division. In North America this genus still outnumbers Lycena, the former having 
fifty-six and the latter forty-eight species, as given in Skinner’s catalogue, whereas in 
Central America the numbers are 215 and 13 respectively. ‘There is a difference of 
opinion as to the true position of Eumeus, and an interesting note by Mr. S. H. Scudder 
(of. IL. pp. 110-112) has been added to our remarks on the genus. 
PAPILIONID&. 
The Papilionide include two subfamilies—the Pierine and the Papilionine ; 
the first-mentioned dividing into two groups, the Pierina and the Dismorphiina. 
Of the Pierina, seventeen genera are mentioned by us as inhabiting Central America. 
Pereute, Leodonta, Catasticta, and Archonias frequent the forest-clad slopes of the 
Cordillera, some of the species attaining a high elevation. Eucheira is confined to 
elevated districts on the plateau of Mexico, living in oak-forests. Hesperocharis affects 
mountainous places, and ranges from South Mexico to the Argentine Republic, about 
one-third of the known species occurring within our limits. The remainder— Pieris, 
Callidryas, Colias, Terias, Nathalis, &c., all widely distributed—frequent open places, 
Terias and Pieris being each represented by numerous species. The typical forms of 
Colias in the New World mainly inhabit North America and the Andes. C. cesonia, 
which is of a somewhat different type, lives in both the low country and the mountains, 
extending northward to the Eastern United States and southward to Bolivia; the two 
BIOL. CENTR.-AMER., Rhopal., Vol. L., November 1901. c 
