422 CLASS viu. 



posterior in the structure of the cells, supplied with basal cell 

 resembling a right-angled triangle inverted. 



Sub-genera : Libellula, Epitheca CHARPENT. (Libella SELYS). 

 Cordulia LEACH. (Epophthalmia BURMEISTER, and other genera of 

 RAMBUR ; see his Nevropteres, pp. 24 152.) 



Sp. Libettula depressa L., R(ESEL, Ins. n., Ins. aquat. Cl. u. Tab. vi. fig. 4, 

 Tab. vii. fig. 3, DUM&IIL, Cons. g. s. 1. Ins. PI. 28, fig. 6; Libellula 

 cenea L. (Cordulia cenea), PANZER, DeutschL Ins. Heft 88, Tab. 20. 



To the right-angled triangle, at the base of the fore-wings, as character 

 of this genus, I directed attention in a short communication in the Bijdragen 

 tot de natuurTc. Wettenschappen. in. bl. 335339. PI. in., and Ann. des Sc. 

 nat. xv. 1823, pp. 424 427. PL xi. b. 



B. Intermediate lobe of labium broader than lateral ; lateral 

 lobes supplied with moveable appendix at apex, sometimes com- 

 posed of many joints. 



jEshna FABR. Eyes large, approximate. Ocelli often disposed 

 in a transverse row. Wings expanded. 



a) With eyes contiguous. 



Sub-genera : Anax LEACH, ^Eshna ejusd., Gynacantha RAMBUR. 

 Sp. jEshna grandis, Libellula grandis L., RCESEL, Ins. 1. 1. Tab. IV. &c. 



b) With eyes approximate, not contiguous, or remote; with Jiead 

 transverse. 



Sub-genus : Lindenia DE HAAN, V. D. HOEV. (Diastatomma 

 BURM.) 



Note. Here are to be referred sub-genera Oomphus, Cordulegas- 

 ter and Petalura LEACH, and some others proposed by RAMBUR, op. 

 cit. p. 153. 



Agrion FABR. Eyes remote. Head transverse, much broader 

 than thorax. Wings narrow, erect when the insect is seated. 

 Middle lobe of labium deeply bifid. Abdomen slender, cylindrical, 

 often very long. 



Sp. Agrion pudla, Libellula puella L. (is a collective name for different 

 European species, and thus it is arbitrary to adopt it as a synonym), Agrion \ 

 furcatum CHAEPENT. ; RCESEL, Ins. 1. 1. Tab. xi. fig. 7 ; Agrion mrgo, \ 

 Libellula virgo L., R<ES. 1. 1. Tab. IX. figs. 5, 6, &c. 



