23 
Key to the Species 
A Antennae with 3rd segment hardly longer than the 4th; segments 6 to 11 distinctly 
stouter than segments 2 to 5; the poriferous areas as oval spots, one on each seg- 
ment; cheeks very short; colour blue. (1) chalybea. 
AA Antennae with 3rd segment much longer than 4th; distal segments slender; poriferous 
areas as grooves or series of pits; cheeks moderate; colour black and reddish. 
B Antennae with poriferous areas a series of pits; pronotum shining feebly punc- 
tured, shorter than the width and very strongly convex; body and elytra 
black, head and pronotum red. (2) capitata Newm. 
BB Antennae with poriferous areas in the form of grooves; pronotum opaque, deeply, 
closely punctured, distinctly longer than the width and only moderately convex; 
body, head, and pronotum black, elytra reddish, 
C Elytra closely punctured, lustre subopaque, colour dull red; pubescence of 
pronotum and elytra rather long and conspicuous; proepistemal area 
closely punctate, moderately excavated, strongly punctate behind the coxae. 
(3) rubida Lee. 
CC Elytra sparsely punctured, lustre shining, colour bright red; pubescence of 
pronotum and elytra very short and inconspicuous; proepistemal area 
sparsely punctate, very deeply excavated, very sparsely punctate behind 
the coxae. (4) keeni Csy. 
(1) Alosterna chalybea Hald., 1853, Trans. Am. Phil. Soc., vol. X, p. 60. 
Length 6 mm. This small, stout species can easily be distinguished 
by its blue colour and the straight basal margins of the elytra. It is appar- 
ently rare in collections. We have never seen a specimen from Canada. 
Three specimens before us are from Ohio and Pennsylvania. Other locali- 
ties mentioned in literature: Canada, New York, North Carolina, and 
Iowa, Six specimens in the Leconte collection are from the Central States 
and Illinois. 
Type locality: Pennsylvania. 
(2) Alosterna capitaia Newm., 1841, Ent., p. 71. 
sanguinicollis Dej., 1837, Dej. Cat., p. 383. 
Length 7 to 9 mm. The apices of the elytra vary considerably, but 
are usually distinctly subtruncate. The prothorax has been constantly 
reddish in all the specimens we have seen. The basal angles are acute, 
only moderately produced, but fit over the humeri to form a continuous 
outline; the proepistemal area is sparsely and feebly punctate. 
Seventy-two specimens have been examined from New York, Ontario, 
and Quebec; other localities mentioned in literature: New Hampshire, 
Pennsylvania, Michigan, Iowa, Ohio, Georgia, Montana, and Massa- 
chusetts. 
Type locality: Trenton Falls, New York. 
(3) Alosterna rubida Lee., 1873, Smith. Misc. Coll. (264), pt. II, p. 224. 
Length 10 to 12 mm. This species can be distinguished readily from 
all other North American species except keeni Csy. by the characters given 
in the key. The distal segments of the antennse, bearing the poriferous 
grooves, are but little enlarged, the elytra are closely punctured, sub- 
opaque, and fulvous, and both pronotum and elytra are distinctly hairy; 
the proepistemal area is closely punctured, moderately excavated, strongly 
punctate behind the coxse. 
Ten specimens of rubida and keeni have been before us and others 
have been examined in other collections. The distribution of rubida in 
this material is in California and Oregon. 
Type locality: California. 
