32 CYRTIDAE OF NORTH AMERICA 



separate projection of the tubercle. The proboscis is greatly 

 elongated, reaching beyond the end of the abdomen in smarag- 

 dinus. The tip of the proboscis is pronged, the labella being very 

 large, as in the genus Bombylius (Bombyliidae) . Near the base 

 of the proboscis are the rather small palpi, slender, pencil-shaped 

 and with several fine bristles at the tip. 



Thorax not so strongly convex as in some of the other genera 

 and the abdomen more slender. Scutellum small, short. Abdo- 

 men six-segmented and tapering. The male genitalia are plainly 

 visible. Thorax and abdomen covered with fine pile which does 

 not conceal the ground color. Legs rather slender but not weak, 

 the tibiae spurred. Wings of good size, the venation much as in 

 Lasia, but the marginal cell is widely open and the veins inclosing 

 the second submarginal are diverging at the tip and not parallel 

 or converging. 



This genus, as Gerstaecker noted in his original description, is 

 close to Lasia, differing in the insertion of the antennae and in the 

 more elegantly formed body. Eulonchus also differs in the posses- 

 sion of palpi and eyes that are contiguous below the antennae. 



Sijnopsis of the Species 



1. Legs altogether yellow 3 



Legs, or at least femora, black 2 



2. Tip of femora and greater part of tibiae whitish yellow, the teguhxe uni- 



formly white tristis Loew 



Legs altogether black, only the knees paler, tegulae margined with l)lack. 



marginatus O. S. 



3. Proboscis curved and longer than the abdomen; usually quite large and 



metallic green in color smaragdinus Gerstaecker 



Proboscis straight and as long as the abdomen, often shorter; smaller species, 

 blue, green or purple in color sapphirinus O. S. 



Eulonchus smaragdinus (PI. IV, fig. 16.) 

 Eulonchus smaragdinus Gerstaecker, 1. c. 



"The body is of a beautiful, shining emerald green, that on the scutellum 

 shows a slight tinge of bluish; the thorax is above as well as below thickly 

 covered with long downy yellowish hair, which stretches back to the scutellum. 

 Much finer and sparser, the hair on the abdomen is also more on the sides, where 

 it is especially heavy on the hind margins of the segments and thickest on the 

 third and fourth. The long hair of the eyes, which is thick and brushy, shows 

 a paler yellow color, more of a whitish. On the antennae the first two joints 

 and the base of the third are tinged reddish, the large i)art of the latter blackish, 

 however. The legs are, with the exception of the coxae, which are the color of 



