112 BROOKLYN MUSEUM SCIENCE BULLETIN 3. 3. 
DoNACiA MEGACORNis Blatcliley. 
Rather short and moderately robust; color aeneous or cupreous; 
legs and antennae generally reddish, rarely the femora with a faint, small, 
dark cloud. 
Head relatively strongly narrowed and constricted behind the eyes, 
which are prominent and rather large; median line deeply impressed; 
posterior tubercles feeble ; surface densely and finely punctate ; antennae 
scarcely reaching the middle of elytra, joints rather stout, second and 
third joints small, equal and together about as long as the first joint, 
fourth joint shorter than the first. 
Prothorax about as wide at apex as long; sides more or less parallel 
behind the lateral tubercle, often diverging towards base; anterior 
angles distinct, occasionally very obtuse, rarely slightly projecting; 
basal angles rounded; median line distinct or absent; anterior im- 
pression absent; posterior impression sometimes distinct, occasionally 
feeble or absent; lateral tubercle feeble; surface more or less strigate- 
rugose caused by confluence of the large punctures. 
Elytra with distinct ante-median and post-median impressions, the 
latter less deep than the former; apices truncate, outer angle distinct 
but rounded; surface moderately coarsely rugose, often smoother in 
the scutellar region and more or less distinctly and finely punctate, 
intervals towards apex transversely strigate-rugose ; serial punctures 
large becoming rapidly smaller towards apex. 
Body below densely and finely punctate and moderately densely 
pubescent with yellow or yellowish-cinereous, short hairs; pubescent 
space near anterior coxae moderately large; intercoxal process of meso- 
sternum about one third the width of the cavities or slightly less ; posterior 
femora reaching the apex of third ventral segment in the male, shorter 
in the female, distinctly clavate, at base slightly narrower than at apex 
and armed below in both sexes with a rather large, triangular tooth, the 
posterior margin of which is crenulate, which can be plainly seen from 
an internal view. Length: 6-7 mm. 
Male: Last dorsal- segment truncate or feebly emarginate at apex; 
last ventral segment depressed at middle of apex. 
Female: Last dorsal segment broadly rounded at apex, sometimes 
apparently slightly emarginate; last ventral segment narrowly rounded 
at apex.' 
Iowa: Iowa City (Wickham). 
Indiana: Lake County, May (Blatchley). 
