LYCAENIDAE. General Topics by Dr. A. Seitz. 739 



9. Family: Lycaenidae, 



The delimitation of this family is not difficult for the American forms either, if the characteristic of 

 the Lycaenidae which are devoid of any real cleaning-paws is to be decisive. Thereby a contrast is effected 

 with the Danaomorphinae, Nymphalidae and Satyromorphinae, in which both sexes, and with the Erycinidae, 

 in which the (^^ exhibit the forefeet transformed into cleaning-paws *). The Lycaenidae are separated from 

 the Papilionidae by such conspicuous diffei'ences of the habitus that not one word need to be said about them. 

 In a similar manner the Pieris exhibit besides the remarkable peculiarity in the subcostal neuration of the fore- 

 wings, a rise of the 3rd, 4th and 5th branches from a joint pedicle, whereas the Lycaenidae exhibit only a two- 

 pronged bifurcation of the veins in the apex of the forewing, if not all the subcostal branches rise separately 

 from one another. Another characteristic mark of the Lycaenidae are the bean-shaped outlines of the eyes being 

 circular or slightly oval in the other day-butterflies. 



So far about 900 to 1000 Lycaenidae have been described from America, less, therefore, than from 

 the palearctic district in which many more names were distributed. But as the names of most of the American 

 forms were allotted to well distinguished species, while those of most of the European forms were given 

 to insignificant sub-forms or aberrative discolorations, the number of the American species is probably 

 twice or thrice as large as that of the whole palearctic district. It has never occurred that an American species 

 has been denominated by more than 20 different names as for instance the palearctic Chrysophanus virgaureae, 

 phlaeas or Lycaena icarus. America, however, is inferior to the Indo-Australian fauna, regarding both the 

 number of species and especially the variety of the genera of which there are more than 120 in the east; in 

 America, however, but quite few. The Ethiopian region, however, is excelled by the American Lycaenidae 

 as to the number of species. From Africa to the south of the Sahara, and from the islands belonging to it, 

 we know about 6 to 700 Lycaenidae, one third of which belong to groups that have no allies in the American 

 district, i. e. the Lipteninae. Such Lycaenid-groups, being to some degree isolated and characteristic of the 

 special district like this subfamily or perhaps the Liphyrini, are not found in the American region; on the con- 

 trary, all the American species belong to such genera that are represented also in the Old World, with the sole 

 exception of few species of the genus Eumaeus to which we shall revert later on. 



In America itself the distribution is similar to that of the palearctic Lycaenidae; in the tropics there 

 are considerably more species, though by no means in such great numbers as for instance the Itfwmiini (the 

 so-called Neotropids) in the equatorial districts, which disappear abruptly on reaching the northern or southern 

 tropics. Not even in one of the Lycaenid-genera containing many more species, the tropics form the delimitation ; 

 except that the insignificant forms of the northern part of North America and the southern part of South 

 America, being allied to the European forms, are replaced in tropical America by brightly coloured and varie- 

 gated, often also very large Lycaenidae. 



The geographical distribution of the Lycaenidae, which exhibits many striking peculiarities, is full of 

 problems also in respect of American species. Some of them have analoga on the eastern hemisphere, just 

 like in New Zealand and Australia there occur forms that have their nearest allies not in the interjacent India, 

 but quite in the north [Chrysophanus salustius, boldenarum, the Lrebia-like Satyrids Argyrphenga etc.); thus 

 also the Lycaenidae, particularly the Thecla, grow, towards the southern point of South America, more and 

 more similar, instead of dissimilar, to the North Americans. These resemblances are undoubtedly due to 

 convergent symptoms, in which similar groups of animals react in a similar way upon the climate which naturally 

 approximates in the extremest south to that of the northernmost region. By this, however, we cannot explam 

 other symptoms, such as the occurrence of otherwise African genera on the high ridges of the Aiides (genus 

 Cyclyrius Btlr.). Such cases must involuntarily rouse the suspicion that these genera are no natural ones, since 

 their homogeneousness was established upon criteria that are not to be understood as the symptom of alliance, 

 but as fortuitous or also as convergencies. 



Of certain palearctic habitats we know that sometimes an enormous number of specimens of Lycaenidae 

 gather there, sometimes entirely of one species, often composed of different species. We have already called 

 the readers' attention to the small water-courses of the Alps, where the alpine Lycaena sometimes gather in 



*) In the (5(5 of the Lycaenidae the forelegs are at any rate smaller than in the $$ and they have a plain ter- 

 minal m^enaber. Cf. Vol. I, p. 257. 



