426 NEUROPTERA 



CHAP. 



Fia 



yet there exist in this remote archipelago several highly- 

 peculiar species of Agriouinae. Mr. E. C. L. Perkins has 

 recently discovered that the nymphs of some 

 of these are capable of maintaining their 

 existence and completing their development 

 in the small collections of water that accumu- 

 late in the leaves of some lilies growing on 

 dry land. These nymphs (Fig. 271) have a 

 shorter mask than occurs, we believe, in 

 any other Odonata, and one would suppose 

 that they must frequently wait long for a 

 meal, as they must be dependent on stray 

 Insects becoming immersed in these tiny 

 reservoirs. The cannibal habits of the 

 Agriouid nyinpii,\vith Odonata probably stand these lily-dwellers 

 short mask, living iu in good stead : Mr. Perkins found that there 



water in lilies. Ha- 

 waiian Islands, x 3. '^v^re Sometimes two or three nymphs of 



different sizes together, and we may suspect 

 that it sometimes goes hard with the smaller fry. The extension 

 in the length of the body of one of these lily-frequenting Agrions 

 when it leaves the water for its aerial existence is truly extra- 

 ordinary. 



The Odonata have no close relations with any other group of 

 Insects. They were associated by Latreille with the Ephemeridae, 

 in a family called Subulicornia. The members of the two groups 

 have, in fact, a certain resemblance in some of the features of 

 their lives, especially in the sudden change, without intermediate 

 condition, from aquatic to aerial life ; but in all important points 

 of structure, and in their dispositions, dragon-ilies and may-flies 

 are totally dissimilar, and there is no intermediate group to 

 connect them. We have already said that the Odonata consist 

 of two very distinct divisions — Anisopterides and Zygopterides. 

 The former group comprises the subfamilies Gomphinae, Cordu- 

 legasterinae, Aeschninae, Corduliinae, and Libellulinae, — Insects 

 having the hinder wings slightly larger than the anterior pair ; 

 while^ the Zygopterides consist of only two subfamilies — Calep- 

 teryginae and Agrioninae ; they have the wings of the two pairs 

 equal in size, or the hinder a little the smaller. The two groups 

 Gomphmae and Calepteryginae are each, in several respects, of 

 lower development than the others, and authorities are divided 



