274 PHYTOPHAGA. [ Donacia. 
head thickly and rugosely punctured; antenne black, with base 
metallic; thorax somewhat longer than broad, closely and deeply 
punctured, with the lateral callosity moderately distinct, and the 
anterior angles obtusely dentate; elytra subparallel until behind 
middle, feebly impressed near suture, rather strongly punctate-striate, 
interstices finely rugose, reticulate, apex truncate; legs unicolorous, 
metallic, femora with a sharp tooth in both sexes. L. 7-9 mm. 
Male with the fifth ventral segment subtruncate, and impressed at 
apex, female with the same segment produced and subacuminate. 
On Seirpus, Carex, &ec., in June; not common ; Caterham, Woking, Bearsted ; 
Faygate, Sussex; Pegwell Bay; Deal; Hastings; Portsmouth district ; Bristol. 
D. impressa, Payk. (? brevicornis, Kunze, nec Ahr.). Closely 
allied to the preceding, but shorter, broader, and more shining, with 
the antennz shorter, and the posterior femora armed with a blunt and 
more or less obsolete tooth; the thorax is less closely and less deeply 
punctured, and has the lateral callosity less distinct, and the impres- 
sions on the elytra are more pronounced; in the colour both of the 
under and upper side it much resembles D. thalassina. L. 63-9 mm. 
On aquatic plants (Carex, &c.), in May; not common; Maidstone; Faygate, 
Sussex (Gorham) ; Sandwich (T. Wood); Hastings district; Bristol; Bretby Park, 
Repton (W. Garneys); Scotland, “Ayrshire, Mr. Hardy,’ Murray’s Cat.; this 
latter record is somewhat doubtful. 
D. simplex, F., Syst. Ent. (linearis, Hoppe; eruginosa, Westh.). 
Elongate, depressed, coppery, reddish, or e#neous green, under-side 
silvery, antenne and legs partly reddish ; head very closely sculptured, 
thorax slightly longer than broad, very closely and rugosely punctured, 
with the central furrow more or less obsolete, anterior angles pro- 
nounced ; elytra long, gradually narrowed to apex in male, more parallel 
in female, obsoletely impressed, broadly truncate at apex, with rows 
of rather shallow punctures, interstices closely rugose, giving the 
insect a frosted appearance ; posterior femora simple in both sexes. 
L. 7-9 mm. 
On aquatic plants; generally distributed throughout the kingdom ; it is one of 
the commonest British species. 
D. vulgaris, Zsch. (typhe, Ahr.). Allied to the preceding, but, as 
a rule, easily distinguished by the broad reddish-purple and blue 
stripe which runs down each elytron near suture ; occasionally uni- 
colorous specimens occur, but these may be known by the shorter 
antenne, much less pronounced anterior angles of thorax, and more 
regular striz of the elytra, which are more parallel and less gradually 
narrowed behind; the pubescence of the under-side is a little darker 
and greyer; the very close sculpture of the thorax and the absence of 
teeth on the posterior femora in both sexes will distinguish it from D. 
thalassina. LL. 6-9 mm. 
