(IEOCRAPHICAL DISTRIBUTION. Lepidoptera oc cur wherever plant-life suited to the nourishment of the caterpillars is present. They are snn-lo•ing forms, and are most numerous in species in the tropics. However, in numbers of individuals. some of the temperate zone forms far outrank any of the others. Some species occur in the Arctic zone and on the tops of snow-clad moun tains. Certain forms flourish in the far north. in Greenland, Labrador. and Iceland, or on tops of snow-capped mountains. Some species are re stricted by temperature or food-plant to a very limited area. while others are practically of world wide distribution. Widely distributed forms either feed on widely distributed plants. or can feed on a. number of different food-plants.
The delicacy of the Lepidoptera has prevented their preservation as fossils. The Ter tiary rocks of the Western United States, and the rocks from the time of the British chalk down, have yielded remains of a few scattered species.
About 50.000 species of Lepidoptera are known, of which 1i.000 occur in -knierica north of Mexico. Of skippers there are two families—the large skippers, Megathymidre, and the smaller skiptiers, Tlesperibli•. The butterflies include the Papili onidie. Lycienidie, and NTymphalidie, and all other families (over 40) belong to the moths.
Biltmomt.UnlY. For general works, see bibliog raphy under INSECTS; A. Hyatt and J. M. Arms,
"Meaning of !Metamorphosis," .Vat ural Science, 1 III. (London. 1S96) ; E. B. Poulton, "Neurol ogy of Pup:e." in Transactions of the Li'nmean. .Society (London, ; T. A. Chapman, "Pupfc of Moths." in Ton/suctions of the Entomological Socicty (London, 11893 ) ; and subsequently W. F. Kirby, Handbook to European Butterflies mid .1/0i/O: (with guide to literature of the order, 5 vols., London. 1895) ; S. II. Scudder, Rutter/Hes of Yea. England (3 vols., Cambridge, I3S9) ; W. J. I Tolland, The Butterfly Book (Ne• York. 1S9S); G. H. French, Butterflies of the Eastern United States (Philadelphia, 1S95) ; A. Weismann, New Experiments on the Seasonal Dimorphism of Lepidoptern, translated by W. E. Nicholson in Entomologist, January-August (London, I 896) ; Walker, British Museum ('utfologue of Lepidop iera ( London. I554-513) ; Herrich-Schaffer, Sys tenintisehe Bearbcitung der Sehmetterlingc von Lurope Ilh•genslyurg, 1843-50) ; Doubleday and Westwood, genera of Diurnal Lepidoptera (Lon don, : H. J. Elwes, "The Distribution of Butterflies," in Proceedings of the Entomolog ical Soriet,y (London, I594); A. S. Packard, Ttxt-Book of Entomology (Yew York, 1898). For works relating to special families and spe cies, see their names.