Feb., 1847.] 159 



beneath dusky silvery-sericeous, with the abdomen, as is common, pale or 

 reddish brown ; femora, excepting at base, blackish ; base of femora, tibiae 

 and tarsi dull rufous ; posterior femora hardly toothed at tip. This is a 

 very rare species. 



" D. metallica. Cupreous; antennae and feet rufous; second and third 

 joints of the former equal." Say, Journ. Acad. Nat. Sc, v. 283, 2. 



Var. c. Blue ; antennae and feet as in the type. 



3. D. biimpressa. Cyaneous ; thorax with an orbiculate impression each 

 side of the middle; elytra finely striate-punctate. 8 1. long; 1 1. wide. 

 Pennsylvania. 



Cyaneous, with a violaceous or greenish reflection, shining : head dull 

 silvery-sericeous, confluently rugose-punctulate, with the frontal line pro- 

 foundly impressed ; antennae moderately long, brown, with the base of the 

 joints more or less dull rufous ; second joint rather shorter than the third ; 

 mouth and palpi brownish : thorax longer than wide, wider at apex than 

 at base ; above tinted with greenish, finely, deeply and distantly punctured 

 medial line fine, more deeply impressed before the middle than towards 

 the base ; a small, suborbiculate, profound impression each side and near 

 the middle ; lateral tubercle moderate, oblong ; anterior angles slightly 

 tuberculate : scutellum dull violaceous, minutely and densely punctured : 

 elytra faintly tinted with violaceous, finely transversely wrinkled, finely 

 striate-punctulate, sutural region obtusely indented in two or three places; 

 an oblique, rather obsolete, indentation from the humeral angles to the 

 suture ; apex obliquely truncate, almost rounded : beneath blackish, densely 

 punctulate, dull silvery-sericeous ; femora blackish or dark brown, with 

 their base, tibiae and tarsi, dull dark rufous ; hind pair of femora with an 

 obvious tooth towards the tip. This species is also very rare. 



Var. a. Elytra violaceous, sculpture rather stronger than in the type ; 

 thorax darker than the elytra, with the two dorsal impressions shallow and 

 somewhat obscure ; bases of the antennal joints more obviously rufous 

 than in the type. Donacea violacea. Melsh. MS. 



4. D. aurichalcea. Brassy-yellow, shining ; antennae with the third joint 

 somewhat longer than the second; thorax distantly punctulate; femora 

 brassy-brown. 3 1. long ; 1 1. wide. Pennsylvania. 



Donacea aurichalcea, Melsh. MS. 



Brassy-yellow, shining : head, color and sculpture as in the preceding 

 species ; antennae moderately long, dull rufous, with the tips of the joints 

 black; two basal joints almost black-brassy; second joint one-fourth 

 shorter than the third : thorax longer than wide, wider at apex than at 

 base ; above distantly punctulate, with the medial line fine, rather obsolete . 

 lateral tubercle moderate, oblong ; anterior angles slightly tuberculate ; 

 scutellum ashy-pubescent, minutely and densely punctured : elytra, apart 

 of the color, entirely as in the preceding species : beneath dull silvery-seri- 

 ceous ; femora brassy-brown, shining, with the hind pair obviously toothed 

 towards the tip; base of the femora, tibiae and tarsi, dull rufous. Though 

 the present species is destitute of the two thoracic impressions, so con- 

 spicuous in biimpressa, it may nevertheless, perhaps, be a variety, if not the 

 type, of that species. 



6. D. rutila. Brassy yellow, shining ; antennae testaceous, with the third 



