XX. A LIST OF THE DRAGON FL IE vS RE-CORDED FROM THE INDIAN EMPIRE WITH SPECIAL REFERENCE TO THE COLLECTION OF THE INDIAN MUSEUM. PART II. THE FAMILY AGRIONINAE. A. The sections Podolestes, Pi^atycnemis, Platysticta AND PrOTONEURA. By F. F. Laidlaw, M.A. (Plates XIII— XV.) Introduction. The following account deals with four sections (or legions to use Selys' term) of the Agrionidae (=Coenagrioninae of Kirby's Catalogue.) The family is the largest of the sub-order Zygoptera ; it consists of insects which are for the most part small and delicate, and its species are numerous and often exceedingly^ abundant in individuals. It is in fact a dominant family of existing Odonata. In the Eastern tropics, so far as my observations go, and probably in most parts of the world this holds good, the members of the family falling into one or other of two great biological groups : — I. Those which appear not to be affected adversely by human activities, have a wide distribution as species, and are abundant in cultivated country ; and probably pass their larval stages in still or stagnant water. Such for example are the species of the genus Ischnura and of Aqriocnemis, which thrive in the environs even of a great city like Calcutta. II. Forms whose habitat is uncleared forest and uncultivated land, which tend to disappear with the advent of cultivation ; whose larvae probably live for the most part in running water. It is noteworthy that such forms as a rule retain certain characters that may be regarded as primitive, though, beyond question, many of them exhibit extreme specialization in certain directions. The sections of the family dealt with in the present paper may be grouped mainly in the latter of these biological divisions.
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