ORTALID.ffi CYRTOMETOPA. 179 



at all ; the hind femora very much incrassated, beset with spines 

 on the under side. 



Wings: the cross veins approximated to each other ; the third longi- 

 tudinal vein towards its tip is more or less curved backwards ; the 

 third and fourth veins, for this reason, appear convergent; posterior 

 angle of the anal cell obtuse. 



The characters distinguishing this genus, which is peculiar to 

 America, are as follows : the rather equally narrow abdomen ; 

 the unarmed front and middle femora ; the very much incrassated 

 hind femora, the under side of which is beset with spines ; finally, 

 the crossveins being approximated to each other. 



The rather coarse hairs upon the feet of most species of 

 Richardia look somewhat like spines at the further end of the 

 under side of the front and middle femora; although I have not 

 observed any real spines upon the under side of the four anterior 

 femora in any of the species which I have examined. 



The mention of the presence of the prothoracic and mesotho- 

 racic bristle has been introduced among the characters of this and 

 of the following genera, wherever I was able to do so. But, as 

 in several cases I had only a single, perhaps not particularly 

 well-preserved, specimen for comparison, or one in which this 

 character could not very well be ascertained, the statement about 

 the absence of one of these bristles is not to be taken too strictly 

 until further confirmation. 



The typical species is the well-known Richardia podagrica 

 Fabr., from South America. 



Gen. III. CYRTOMETOPA nov. gen. 



Charact. Front broad, very much projecting in profile. 

 Arista pubescent. 

 Femora strong, although not exactly incrassated ; all are beset with 



spines. 



Wings : posterior angle of the anal cell obtuse ; crossveins not approxi- 

 mated to each other ; the end of the fourth longitudinal vein con- 

 verges very much towards the tip of the third vein. . 



The typical species is the Odontomera ferruginea Macquart 

 (Dipt. Exot. II, 3, p. 215), in which, with tolerable certainty, I 

 recognize an American species. 



The Odontomera maculipennis Macquart (Dipt. Exot. Suppl. 

 I), from Columbia, probably belongs to the genus Coelometopia. 



I have drawn the characters of this genus, as far as it was 



