158 CONNECTICUT GEOL. AND NAT. HIST SURVEY. [Bull. 



dorsal margin convex and obliquely rounded at apex, bluntly 

 and roundly pointed above; third segment of the antennae as 

 long as the fourth and fifth together, the fourth and fifth sub- 

 equal, the second broader than the fourth. Length 3 mm. 

 Larva mines the leaves of the European alder. 



SCOLIONEURIN^. 

 Key to Genera. 



1. Antennae with second segment annular, broader than long; 



first and second segments together shorter than third.... 2 

 Antennas with second segment distinctly longer than broad; 

 first and second segments together as long as or longer 

 than third Melanobates p. 158 



2. Eyes with their inner margins straight and parallel, not con- 



verging below ; front distinctly wider than high 



Polybates p. 158 

 Eyes with their inner margins uniformly convex and con- 

 verging below; front not as wide as high . .Metallus p. 159 



Melanobates MacGillivray. 



M. leucostomus Rohwer. 



Body black, with the clypeus, labrum, basal half of the mandi- 

 bles, angles of the pronotum, and tegulse, white ; legs below the 

 knees brownish white; front around the base of the antennae in- 

 distinctly punctate; median fovea large, circular, and not' 

 sharply defined ; antennal furrows punctiform above the ocelli ; 

 third antennal segment longer than the fourth; the stigma 

 rounded on the radial margin, broadest at the middle. Length 

 3 mm. 



Polybates MacGillivray. 



P. slossonae MacGillivray. 



Lateral foveae united with the antennal fovese; vertical fur- 

 rows punctiform ; ocellar furrow distinct, broadly concave 

 behind; ocellar basin strongly convex, slightly depressed in front 

 of the median ocellus; median fovea deep, punctiform; an- 

 tennae slender, the first and second segments together less than 

 half the length of the third; wings hyaline, the veins, costa, and 

 stigma brown ; stigma over twice as long as wide, its hind margin 

 uniformly convexly rounded; saw-guides straight above and 

 below, converging to a bluntly rounded point at apex ; body 

 black, with all the legs entirely white. Length 3 mm. 



