154 DIPTERA OF NOBTH AMERICA. [PART II. 



ments ; the hypopygium is very small, entirely imbedded and 

 without bristles ; its appendages are extremely small, almost com- 

 pletely hidden. The female abdomen shows only five segments. 

 Feet rather long, moderately bristly ; the first joint of the hind 

 tarsi without bristles, much shorter than the second ; the pulvilli 

 on the fore tarsi of the male are enlarged, but not elongated. 

 Wings of rather uniform breadth or narrower towards the root ; 

 the first longitudinal vein not elongated; the last segment of the 

 fourth longitudinal vein though somewhat inflected, still rather 

 parallel with the third. Eutarsus appears to be nearer related 

 to Di&phorus than to any other genus. The striking smallness 

 of the palpi, the face narrowed below, the hypopygium covered 

 with but delicate hairs, the very small and almost completely con- 

 cealed appendages of the hypopygium and the not elongated pul- 

 villi of the fore tarsi in the male distinguish Eutarsus from 

 Diaphorus sufficiently. From Nemato])roctus, whose exterior 

 appendages of the hypopygiuln arc long threads covered with 

 hair, Eutarsus is distinguished by the small and concealed ap- 

 pendages of the hypopygium. The species of Saucropus cannot 

 be confounded with the species of Eutarsus on account of the en- 

 tirely disengaged hypopygium. 



The genus has been founded upon the well known European 

 Eutarsus aulicus Meig. The name (from si, handsome, and 

 rapaoj, foot) has reference to the structure of the feet of the male. 



As yet no North American species is known to me, but I know 

 a species from Venezuela, the hind tarsi of the male of which 

 have a remarkable structure, and of which I furnish a description. 



1. E. eques, n. sp. %, . — Chalybeus, modice nitens, abdominis ex 

 seneo nigri maculis lateralibus, ventre pedibusque flavis, fernoribus pos- 

 ticis supra tibiisque posti'cis totis fnscis, tarsis anterioribus pragter 

 basim, posticis totis nigris, articulo horum primo brevissimo, quarto in 

 aculeuui producto. 



Steel-blue, moderately shining; lateral spots of the bronze-black abdomen, 

 venter and feet yellow ; upper side of the hind femora and the whole 

 hind tibire brown ; the four anterior tarsi with the exception of the root, 

 and the whole hind tarsi black; the first joint of the latter very short, 

 the fourth joint produced into a point. Long. corp. 0.27. Long. al. 

 0.26. 



Male. Front shining steel-blue, not very broad, not excavated 

 on the vertex. Antennae only of moderate length, black ; the 



