268 MANDIBULATA. — COLEOPTERA. 



In addition to the dissimilarity in tlie form of the tarsi and 

 structure of the antennae, the Donacise are distinguished from the 

 insects of the following genus by the brilliant metallic hues which 

 adorn the body, and by the apex of the elytra not being mucronated 

 or having a spine : — they are nearly all subject to considerable 

 variety in colouring, some of the species partaking of every tint, 

 while others are more constant in the appearance ; they reside in 

 marshy places ; their larvse subsisting upon aquatic plants. 



A. The posterior femora with two or three teeth towards the apex. 



Sp. 1 . crassipes. Depresso-plana, supra violacea, subtus argenteo-sericea, thoracis 

 disco canaliculato Icevi, elytris profunda punctato-striatis, interstitiis lavibus, 

 femoribuH posticis longissimis arcuatis, in maculis tridentatis in Jwminis, uni- 

 dentatis. (Long. corp. 4—5 lin.) 



Do. crassipes. Fabricius. — Steph. Catal. 207. No. 2097. 



Depressed, above violaceous, or greenish, with a brassy tinge, beneath clothed 

 with a silvery silken pubescence : head black : thorax with an abbreviated 

 longitudinal canal, the disc on each side within the anterior angle, with an 

 elevated rounded tubercle, and a somewhat deep curved fovea, and towards 

 the base with an obsolete transverse impression ; in other respects smooth, or 

 very finely coriaceous; the sides a little greenish : e/y^ra deeply punctate-striate, 

 with the interstices smooth, the margins and apex slightly tinted with greenish : 

 legs dull testaceous, with the femora and tibiae above fuscous : the femora 

 clavate, and the posterior very much elongated and bent, with the base very 

 slender, of the male with three teeth towards the apex, the middle one largest, 

 and of the female with one tooth, corresponding with the middle one of the 

 male : antennae black, with the basal joints ferruginous within. 



Occasionally abundant on the banks of the Thames about Brent- 

 ford and Kew, and in other parts of the metropolitan district. 

 " Prestwick Car." — G. Wailes,Esq. "Upperby." — T. C Hey sham, 

 Esq. " On the waterlily, Windsor." — Mr. G. Waterhouse. 



Sp. 2. cincta. Convexior, supra viridi-wnea, violaceo micans, subtus argenteo- 

 sericea, elytris crenato-striatis, interstitiis thoracisque dorso tra?isvers)m ru- 

 gosis,femoribus crassis fusco-violaceis, posticis minus elongatis maris dentibus, 

 duobus acutis,foemince dente unico. (Long. corp. 3^ — 4 lin.) 



Do. cincta. Gerviar. — Steph. Catal. 206. No. 2096.— Le. aquatica. Martyn, 

 C. p/. 28./ 16, 17. 



Rather convex, above brassy-green, tinted with violet ; beneath clothed with a 

 silvery-silken pubescence : head fuscous : thorax with an abbreviated longi- 

 tudinal furrow, an oblong tubercle within each anterior angle and the disc 



