LIBELLULID^. LIBELLULA. 91 



A. Abdomen depressed and dilated: — Platetrum, Newman. 



Sp. 1. depressa. Abdomine lato, depresso, maculis lateralibus luteis, alls anticis 

 macula oblongd baseos posticis 3-anguIari Juscis, membranula accessoria alba. 

 (Long, corp 1 unc. 8 — 9 lin.; Exp. Alar. 2 unc. 10 lin. — 3 unc.) 



Li. depressa. Linnc. — Donovan, v. i. p. xxiv. 9 . v. iii. pi. 81. $ . — Steph. Catal. 

 310. No. 3445. 



Head fuscous; thorax reddish-brown, palest above, with two longitudinal 

 whitish streaks ; abdomen frequently blue above, sometimes brown or 

 testaceous, more or less of the intermediate segments with a rounded yellow 

 spot on the sides ; anal appendages small and black ; wings hyaline, stigma 

 black ; anterior pair with an oblong fuscous spot, veined with deep tawny ; 

 posterior pair with a similar spot of a triangular form ; accessory membrane 

 white ; legs black ; femora red. Female with the thoracic streaks lutescent, 

 the abdomen generally of an olivaceous tinge, with most of the segments 

 bearing a luteous spot on the sides, and the three last with a black dorsal 

 line. 



Very abundant, throughout the metropolitan district, from the end 

 of May ; taken also in the New Forest and near Dover ; in Devon- 

 shire, Cambridgeshire, Norfolk, Suffolk, &c. 



Sp. 2. conspurcata. Abdomine depresso, supra cwrulescente (mas), aut rvfo, 

 stigma dorsali nigra (fcetnina), alis omnibus strigd marginali Jlava, posticis 

 tinea et macula Z-angulari baseos Juscis, membranula accessoria nigricante. 

 (Long. corp. 1 unc. 7 — 8 lin. ; Exp. Alar. 2 unc. 7 — 9 lin.) 



Li. conspurcata. Fabricius. — Sowerby, Brit. Mis. v. i. pi. 46. — Steph. Catal. 

 309. No. 3443. 



Head and thorax fuscous ; abdomen above bluish, with the base and apex 

 fuscous j anal appendages curved ; legs black ; wings hyaline, with an 

 indeterminate yellow or pale orange streak from the base to beyond the 

 middle, tip fuscous ; stigma black ; the anterior have a faint line at the 

 base, the posterior a similar line and a triangular blotch fuscous, the latter 

 is reticulated with bright tawny; accessory membrane dusky. Female pale 

 rufous, the abdomen with a black dorsal line from the 4th to the 9th seg- 

 ments, increasing in width on the hinder margin of each segment; legs black, 

 femora red. 



The wings have sometimes a large blackish spot at the extreme tip, and at 

 others are wholly destitute thereof, and intermediate grades occur : in some 

 examples the wings are almost entirely yellow. 



Found, though not very commonly, in the marshes about Ber- 

 mondsey and Deptford, in June, but abundant in the neighbourhood 

 of Norwich. 



M 2 



