160 DIPTERA OF NORTH AMERICA. 



indubitable that he has been deceived relatively to the true charac- 

 ters of the genus Ochthera, and it is to be supposed that his OcJdhcra 

 empiformis is an insect belonging to the Tachydromidse. 



Synopsis of the Species. 



( Face with deep black furrows and dots. 1 exsculpta, n. sp. 



( Face without black furrows and dots. 2 



9 ( First joint of the hind tarsi but little swollen. 2 mantis Deg. 



i First joint of the hind tarsi much swollen. 3 



( Tarsi black, face broad. 3 rapax, n. sp. 



( Tarsi red, face narrow. 4 tuberculata, u. sp. 



1. O. exscillpta LOEW. . Fades angustissiuia, lineis punctisque 

 exsculptis ornata ; tibiae anticae rufae. 



Face exceedingly narrow, with shining-black furrows and impressed black 

 dots ; fore tibiae red. Long. corp. 0.16. Long. al. 0.16. 



A readily distinguished species, not quite equalling the three 

 following in size. Front narrower than in all the other known 

 species, almost entirely covered with a large shining spot having 

 the form of a regular trapezium, near which the color is velvety- 

 black at the borders of the eyes and brownish on the anterior cor- 

 ners of the front. Eyes larger and longer than in the other spe- 

 cies. Face unusually narrow, dusted with yellow ; a shining black 

 furrow runs from the tubercle placed in the middle of the face to 

 the border of the mouth, and has on each side a similar furrow, 

 the under part of which is laterally continued in a parallel direction 

 to the border of the mouth ; the lateral parts of the face have 

 some impressed, rather coarse, dots. Clypeus sensibly smaller 

 than in the other species. The fore femora black ; the fore tibia? 

 and tarsi red, the first joint of the latter a little longer and a little 

 less pear-shaped than in the other species. The middle and the 

 hind legs black ; the tips of the knees and the tibia? on their first 

 third red ; the first joint of the middle tarsi red as far as the tip, 

 the following joints being so only at the base ; the first joint of 

 the hind tarsi is very little swollen, the second and following joints 

 red at the base. 



Hob. Cuba. (Poey.) 



