306 PROCEEDLNGS OF THE NATIONAL MUSEUM vol. loe 



Latheticomyia, new genus ' 



Type species : Latheticomyia tricolor, new species. 



Rather slender, medium-sized flies (2.5-4.0 mm.), mostly black with 

 prominent yellow areas on head, mesonotum, scutellum, pleura, and 

 legs. 



Head: Postvertical bristles convergent, cruciate in infumata, less 

 strongly converging in tricolor and lineata; inner and outer verticals 

 strong, normal in position; occiput flat or a bit concave; ocelli on a 

 small raised prominence, the ocellar bristles strong, proclinate and 

 divergent, their bases within the ocellar triangle; front longitudinally 

 depressed to sunken between the orbits, becoming deeper anteriorly; 

 each orbit mth three reclinate orbitals, the anterior one close to an- 

 tennal base; orbits, between antennae and anterior orbitals, rather 

 thicldy haired; mesofrons with small hairs, no bristles. 



Antennae somewhat porrect, both basal segments with evident 

 hairs; arista weakly pubescent, inserted dorsally and subapically; 

 face flat and retreating in profile, sunken in the middle, without 

 foveae, and bearing small fine hairs on the upper part between an- 

 tennae (see species descriptions for quantity and color); one pair of 

 moderately strong vibrissae, the following oral hairs mostly small, the 

 row ending with a prominent buccal bristle; palpi of normal size and 

 shape. 



Thorax: Five pairs of dorsocentral bristles of which three are 

 clearly postsutural, one pair is at about the sutural level, and one pair 

 is clearly presutural; prescutellar acrostichal bristles small or absent; 

 acrostichal hairs present; scutellum small and flat, with small scattered 

 hau's on the sides and the disc sparsely haired or bare; six large mar- 

 ginal scutellar bristles, the apical pair largest and cruciate or nearly 

 so. Other bristles are present as follows: 1 proplcural (borne on the 

 apex of a short peduncle), 1 humeral, 2 notopleural, 1 presutural 

 (=posthumeral), 2 alar (apparently 1 supra-alar and 1 post-alar), 

 2 sternopleural; the mesopleura entirely bare. 



Legs: First femur with moderately stout bristles; third femur 

 with a single enlarged bristle at about one-fourth from apex (strongest 

 on tricolor); tibiae without evident preapicals, a moderately strong 

 apical on 2d tibia, a weaker one on 3d tibia. In males of tricolor the 

 first metatarsus bears an apical thumblike projection on its inner 

 side, absent on females. 



Wings: Venation of the general acalyptrate type; costa reaching 

 4th vein; costa broken or weakened just beyond humeral crossvein 

 (not always easily seen), and a definite costal incision just before 

 apex of first vein; subcostal (auxiliary) vein strong basally, weaker 



* Latheticomyia: constructed from tlie Greek lalheticos (addicted to concealment, that easUy conceals 

 ltselt)+myia (a fly); the name is feminine. 



