268 PIIVTOPHAOA. [Donaciu. 



A. Disc of thorax finely or very finely strigose, 



not or scarcely punctured. 



a. Posterior femora very long, reaching apex 

 of elytra ; posterior tibiae of male with 

 prominences on their inner side ; average 



size larger D. CBAS8IPES, F. 



b. Posterior femora shorter, not reaching 

 apex of elytra ; posterior tibia- of male 

 without prominences ; average size 



smaller D. SPAHOANII, Ahr. 



B. Disc of thorax more or less plainly punc- 



tured and coarsely strigose. 



a. Elytra broader and less narrowed behind ; 

 posterior femora of female with only one 



small tooth D. VEKSICOLOREA, Brahm. 



(bidens, Ol.) 



b. Elytra narrower and more narrowed 

 behind ; posterior femora in female with 



two teeth, the inner one being small . . D. DKNTATA, Hoppe. 

 2. Posterior femora of male with one tooth on 

 their under-side. 



A. Posterior femora longer, reaching apex of 

 elytra, each of which is furnished on each 

 side with one impression before middle near 

 suture, and a broad longitudinal purple- 

 red stripe (sometimes more or less obsolete) 



near suture D. DENTIPES, F.* 



B. Posterior femora shorter, not reaching apex 

 of elytra, which are furnished with two or 



more distinct impressions. 



a. Elytra with a longitudinal band at sides, 



and a spot at base purple red . . . . D. LIMBATA, Panz. 



(lemnce, F.) 



b. Elytra unicolorous, or slightly darker 

 on disc, without distinct bands or 



markings. 

 a*. Interstices of striae of elytra rather 



thickly set at base with large punc- 

 tures ; average size larger. 



af. Upper surface golden green ; elytra 

 with six well-marked impressions on 

 each, situated both near suture and 

 at sides ; central furrow of thorax 



deeper D. BICOLORA, Zsch. 



(sagittarice, F.) 



bf. Upper surface obscure brownish- 

 bronze, with distinct impressions 

 near suture, and at most one dis- 

 tinct longitudinal impression at 

 sides ; central furrow of thorax less 

 marked D. OBSCURA, Oyll. 



* The name D. aquatica, L., ought, apparently, to be applied to this insect, but 

 the name aquatica has been given to so many of the species that it is best omitted 

 altogether. 



