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. 



