NOTES ON ODONATA. 17 



by the reflection of the sun's rays from the metallic surface of 

 that insect. 



Platijcneinis pennipes, Pall. — Very abundant at Oxford in 

 June. First observed on June 7th (male var. lactea), it was still 

 plentiful on June 19th. 



Erijtliromma naias, Hans. — This dragonfly was exceptionally 

 plentiful. It was taken in large numbers at Burnham Beeches, 

 Bucks, on June 23rd ; it was abundant at Shenley on June 24th, 

 scarce during July in that locality, but exceedingly abundant at 

 the Aldenham Reservoir on July 29th. 



The last specimen was taken near Tunbridge Wells on 

 August 29th, a very late date for this insect; it was of the 

 male sex. 



Pyrrhosoma nymphula, Sulz. — A single male at Oxford on 

 June 19th. Very plentiful in North Wales at the end of June, 

 and also at Burnham Beeches, Bucks. A few were taken near 

 Tunbridge Wells on August 3rd and 4th. The variety "melano- 

 notum, Selys," was found in Wales. Many specimens were found 

 in spiders' webs at a lake in Carnarvonshire in June. 



P. tenellum, Linn. — This small dragonfly was found so plenti- 

 fully near Tunbridge Wells in August as to rise up out of the 

 grass in swarms. The variety " <eueai?i>/i " was observed. The 

 insect behaved towards S. vietallica like L. sponsa. 



Isdiniira elegans, Van der L., was found uncommonly in 

 Oxford during June, and round Tunbridge Wells in August. It 

 was plentiful at Shenley from June to the end of August, the 

 female var. rufescens being taken abundantly, and the var. 

 infuscans once on July 25th. 



Agrion pulchelluni, Van der L. — Extremely abundant at Ox- 

 ford in May and June, and showing a great tendency in markings 

 in many cases towards the next species. 



A. paella, Linn. — A few taken at Oxford in June. It was 

 found in swarms at Burnham Beeches on June 24th, and was 

 generally plentiful at Shenley through July. A few were taken 

 on August 3rd in Sussex. I was greatly surprised to find no 

 trace of the insect in Carnarvonshire, though I diligently searched 

 for it ; there is a record of it from Tan-y-Bwlch in Mr. Lucas's 

 * British Dragonflies ' (1899, p. 289) ; I was unable to find it in 

 that locality. 



Enallagma cyathigerum, Charp. — This was the most plentiful 

 dragonfly observed. In June, July, August, and the beginning 

 of September it was very common in Hertfordshire, in June at 

 many lakes in Carnarvonshire and in Sussex it was swarming 

 round the ponds near Tunbridge Wells during August. All the 

 varieties of the male were taken, the one with the spot on segment 

 two of the abdomen resembling that of Agrion mercur'iale being 

 exceedingly rare, while the opposite variety with the spot reduced 

 was exceptionally common. The blue variety of the female was 



ENTOM. — JANUARY, 1910. C 



