Vol. XXIX, pp. 89-92 June 6, 1916 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



DRAGON-FLIES FROM THE ENGLISH OLIGOCENE. 

 BY T. D. A. COCKERELL AND HAZEL ANDREWS. 



The material described below was collected by the Rev. P. B. 

 Brodie in the Oligocene beds at Gurnet Bay, in the Isle of 

 Wight, and represents the Oligocene Odonate fauna of Britain, 

 as far as we know it to-day. It is noteworthy that two of the 

 species have Indo-Malay aflBnities; one represents a genus which 

 existed in Europe and America in Tertiary times, but is now 

 confined to America; the fourth belongs to a genus still present 

 in Britain. The specimens are all in the British Museum. 



Oligoaeschna (?) anglica new species. F\g. 1. 



Costo-apical region of wing preserved. Stigma elongated (length 4 

 mm.), bounded by 2)4 cells below; five cells on costal margin beyond 

 stigma; below the base of stigma are two rows of cells between Mi and 

 M2, but M2 is then deflected strongly downward, and the rows of cells 

 increase to three, and toward the apex of the wing, where they become 

 small and irregular, to four or more; M2 separated from Rs by two rows 

 of cells, the number not increasing below base of stigma, where the in- 

 terval is conspicuously greater; Rs separated from supplementary vein 

 below by a single row of cells. The part of the wing preserved is hya- 

 line. 



Gurnet Bay (Brodie). British Museum, 8649. 



This could be referred to Oligoaeschna of the Indo-Malay region or 

 Gomphaeschna of the nearctic. The strong downward bend of M2 is like 

 that of Oligoaeschna, as is also the shape of the stigma; so the indica- 

 tions, as far as they go, are in favor of Oligoaeschna rather than Gom- 

 phaeschna. The remarkable bend of M2 occurs also in the Jurassic 

 genera Cymatophlebia and Morbaeschna. 



Opionaeschna vectensis new species. Figs. 2, 3, 4. 



The type shows the stigma with adjacent parts, and has the following 

 characters: Stigma, 5 mm. long, bounded by 3)4 cells below; M2 bent 

 downward below base of brace-vein of stigma, and at this point the cells 



20— Pkoc. Biol. Soc. Wash.. Vol. XXIX. 1916. (89) 



