I 



Vol. XX Vi] ENTOlfOLOGICAI. NEWS 3 



I. Distribution op the Nymphs. 



There are already on record some general observations on 

 the habitat of dragonflies, as in Needham and Hart, 'oi. and 

 on their distribution in relation to the velocity of water (Need- 

 ham, '02). In this paper some further ecological notes are 

 added and the rfistribution of 30 species, comprising the 

 odonate population of the small area just described, is re- 

 corded. 



P ' IS arc tew. i he (lanisci-ny, Arjui putrida, 



is I -tones in the swift water above the branch- 



ing of the creek, and the dragonfly, CorduUgaster diastatops. 

 in the nearby gravel. T r. covered with sand and with 



the eyes and caudal resj opening arched to the surface. 



lie quietly waiting for their prey to come within reach of their 

 labia. The>' are provided with two strong claws on each leg 

 with which they are able to crawl over the bottom. The flat, 

 sprawling Ophiogomphus lies in the gravel a little farther 

 down stream, where the water flows less rapidly. Ever>where 

 at the cdjjes of the current the damsd fly, CaJoptrryx ttiacu- 

 lata. clinii>s awlcwardly about the weeds and roots, usually 

 iK-.tring aloft the three caudal gill plates. In this position they 

 can perhaps see their prey more readily as it moves by or is 

 swept past by the current. Hetatrima amerieama is also found 

 on the weeds in rapid water, the imago appearing in the field 

 Au'.Mi-it 6th for the first time. 



< Miict water forms are more numerous. Large mmibers of 

 i: •ii'.^hus descriptus, G. spicahts, G. vUlosipes and G. sordid us 

 I>i:rr. av in the soft mud of the sluggi.sh part of the stream .ind 

 esjKvi.illy near the head of the pond. A net swept through 

 the debris along the edge of the pond will occasionally catch 

 what seems at first a very dark, almost black leaf, but which 

 on closer examination proves to be the thinnest, broadest and 

 most grotesque of all the n>'mphs, Hagemus brnnstytus. Be- 

 sides these there are little short "masked** Libellulids which 

 He half buried in the mud or crawl about over the bottom of 

 the ix>nd or on the PJodea or other water wee<ls close to it. 

 Lihellula pulchetta. Ltucorhinia intacta. Ptaihrmis lydia and 

 Packydiplax longipemus are all represented in this group. 



