270 ENTOMOLOGICAL NEWS [J une > ' ! 3 



ages (in several species the appendages are not visible). 

 First joint of hind tarsus of the male longer than the second ; 

 hind tarsi shorter than their tibiae, and the first joint without 

 large bristles above. Wings with the second vein almost 

 straight ; third and fourth veins slightly convergent ; fourth 

 vein ending in or before the apex of the wing. Dorsum of 

 the thorax convex on the posterior end, without a flattened 

 space before the scutellum. (This last character must be used 

 with caution as there is a slight concavity before the scutel- 

 lum, at least in some species, which leads to placing species 

 of this genus in Neurigona, from which they are easily sep- 

 arated by the six-segmented abdomen.) 



In all the species I have seen the hind tibiae are more or 

 less enlarged at the tip. 



Table of Males. 



1 Hypopygium large, making up nearly half the length of the ab- 



domen. Antennae yellow, third joint black. Thorax dark 



green above. (Grenada.) frater Aid. 



Hypopygium smaller 2 



2 Plypopygium very asymmetrical 3 



Hypopygium symmetrical 5 



3 Antennae yellow : first joint of fore tarsi with three or four 



minute but stout black bristles below. (Mexico.) .coxalis Aid. 



Antennae black; fifth joint of fore tarsi with a projection below 



( St. Vincent.) 4 



4 Fore tibiae with a row of stubby bristles similis Aid. 



Fore tibiae without a row of stubby bristles falco Aid. 



5 Fourth vein ending in the tip of the wing 7 



Fourth vein ending before the tip of the wing 6 



Antennae black; first joint of hind tarsi longer than the second, 



6 Antennae with the first two joints yellow, third joint blackish; 



first joint of hind tarsi a little shorter than the second, and 

 the third a little shorter than the fourth. (Sitka. ) 



tertianus Loew. 



Antennae black; first joint of hind tarsi longer than the second, 

 and the third longer than the fourth. (Wyoming.) 



marcidus Wheeler 



7 Pulvilli of fore tarsi not enlarged; first joint of hind tarsi shorter 



than the second, at least in lincatns 8 



Pulvilli of fore tarsi enlarged; first and second joints of hind 

 tarsi nearly equal, or the first longest 9 



