35 



THE DRA.GONPLIES OF THE CHESTER DISTRICT. 

 By J. Arkle. 



Some three or four years ago, in my entomological.wanderings, 

 it occurred to me, when a dragonlly crossed my path, that it 

 might be interesting to give some attention to these extraordinary 

 creatures, and ascertain, as far as I could, how many species were 

 to be found in this district. The Chester Natural Science Society 

 covers the northern half of Wales, as well as the county of 

 Cheshire. In this district we have heaths and mosses, lakes and 

 meres, rivers and streams, — all favoured haunts of the order 

 Odonata. 



If we turn to a list of British dragonflies — say, that of Mr. 

 W. Harcourt Bath— we find ourselves among " nymphs," true 

 "dragonflies," " emeralds " and "elfs," "darts" and " sphinxes," 

 " demoiselles," " sylphs," and " fays." Such are the quaint, 

 mother-tongue names given to the weird and beautiful insects 

 which are the subjects of this chapter. A closer study of the list 

 shows an additional and more scientific nomenclature. First of 

 all, we find there are forty-six species claimed as British. But 

 so many of these rest on such slender claims that the author 

 referred to, in his ' Illustrated Handbook,' p. 13, estimates the 

 number of truly indigenous forms at no more than thirty-seven. 

 Still keeping to our list, we find the forty-six species divided into 

 two great sections — Libellulina and Agrionina. 



Section I. is subdivided into two tribes — Libellulina and 

 ^scHNiNA. Tribe 1 is again divided into two families — Libel- 

 LULiDA and Corduliida. Then we get the Libellulida separated 

 into genera — the Leucoo-rhinia, Sympetrum (nymphs), Platetruni, 

 LihelUda, and Orthetrum (dragonflies). The Corduliida are a 

 single genus, Cordalia (emeralds). Tribe 2 (J^^schnina) is divided 

 into the two families GoMPHiDiB andiEscHNin^. The Gomphida 

 are subdivided into the genera Onychogomphus, Gomijlms (elfs) ; 

 Corduleyaster (darts) ; the iEscHNiD^ into Aiiax, Brachytron, and 

 Mschna—Qjll sphinxes. 



Section II. — the Agrionina — comprises two families, the 

 CALOPTERYGiDiE and the Agrionida. The Calopterygida are 

 represented by the solitary genus Calopteryx, or demoiselles, 

 but the Agrionida by six genera — Lestes (sylphs), Platycnemis 

 (fairies), Erythromnia, Pyrrhosoina, Ischnura, and Agrion — all 

 fays. 



So far, I have taken fourteen species in the Chester district. 

 They are as follows, together with a very brief descri]3tiou, 

 localities, and times of appearance : — 



Leucorrhinia diibia. This is, perhaps, our best dragonfly. It 

 has a large, black, triangular spot at the base of each under 

 wing. Heaths in the Delamere district. Very local. June and 

 July. 



