4 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 7?. 



eclly belonging to this genus, and another which agrees with the gen- 

 eral description of the genotype, but differs in the bristling of the 

 vertex and in some other respects. I deprecate the erection of 

 monobasic genera and, as I find included in some related genera 

 species which differ in a similar manner, I do not propose to erect a 

 new genus for the species now before me. 



All of the species have the basal and second antennal segments of 

 about the same length, the first haired below, the third not less than 

 six times as long as wide at middle, the arista plumose, face promi- 

 nently protruded and convex, thorax with two pairs of postsutural 

 dorsocentrals, no presutural (posthumeral), and one sternopleural ; 

 scutellum bare, flattened above, and with four bristles. The vena- 

 tion is different in folpalis from that of the other species. In three 

 the wings are marked with fuscous, and the second, third, and fourth 

 segments of fore tarsi of all five are compressed. 



I present below a key for the identification of the species, the geno- 

 type being unknown to me except from the description. 



KEY TO THE SPECIES OF ASILOSTOMA 



1. Distance from bases of antennae to lower margin of face not half as great as 



that from bases of antennae to vertex ; frons testaceous yellow, except the 

 dark ocellar spot, face concolorous, the lower lateral angles and most of 

 the cheeks glossy black: labruni large, its area almost as great as that of 

 face, glossy black ; palpi deep black, and much dilated ; anterior pair of 

 orbital bristles about as long as posterior pair, and close to middle of frons. 



palpalis, new species. 

 Distance from bases of antennae to lower margin of face not much less than 

 that from bases of antennae to vertex ; frons and face black ; labrum nar- 

 row ; palpi slender 2 



2. Anterior pair of orbital bristles not half as long as posterior pair; legs 



entirely stramineous 3 



Anterior pair of orbital bristles fully as long as posterior pair ; legs yellow, 

 fore tibia and fore metatarsus, except apex of latter, black. 



enderleini Hendel. 



3. Frons and face glossy black pallipes, new species. 



Frons with a large velvety black mark in front, the remainder glossy black__4 



4. Face entirely glossy black atriceps, new species. 



Face and cheeks entirely glossy yellow flavifacies, new species. 



ASILOSTOMA PALPALIS, new species 



Male. — Head shining testaceous yellow, ocellar spot, a large mark 

 on each side of upper half of frons, and the lower lateral angle of 

 face and contiguous portion of each cheek, black; upper side of 

 basal segment of antennae, and the third segment except base 

 fuscous ; palpi black, arista yellow, the hairs brownish. Thorax and 

 abdomen brownish yellow, a dark streak over each humerus, and a 

 velvety black vitta along upper lialf of pleura and sides of abdomen. 



