464 



■UNITED STATES NATIONAL MUSEUM BULLETIN 2 24 



with the tenth segment wedged into the ninth. Engel 

 gave only one species for this subgenus and I have seen 

 only one. Length 18 to 24 nun. 



Head, lateral aspect: The face is quite plane. The 

 proboscis is robust with well developed dorsal ridge 

 and quite short, unusually regular coronal fringe of 

 apical pile in one row. Occiput at upper eye corners 

 with 4 stout bristles and only the lower eighth of occiput 

 expanded on account of the recession of the eye. Palpus 

 unusually slender and with stout apical bristles. The 

 third antennal segment is slender and long oval. The 

 moderately long style is scarcely or not at all thickened 

 at the apex. 



Head, anterior aspect: The face and front are un- 

 usually wide. The face is only slightly divergent below 

 and bears only moderately stout bristles above the 

 epistomal margin; these stout bristles are continued 

 down along the sides of the subepistoma. There are 

 more slender bristles above on the lower half of the face 

 and scattered, rather numerous, coarse hairs on the 

 upper half of the face with the midline bare. The front 

 is short, with a prominent, transverse groove on its ante- 

 rior portion before the antennae ancl the antennae are 

 set far apart. Vertex deeply excavated but with 

 broadly sloping sides ; ocellarium exceptionally low and 

 without pile or bristles, except for 2 or 3 fine, posto- 

 cellar hairs. 



Thorax : Tlie scutellum and mesonotum have strongly 

 differentiated bristles, the acrostical pile well differen- 

 tiated. Sui-face of scutellum pollinose with stout bris- 

 tles along the middle in addition to the marginal bristles 

 and with numerous, long, coarse hairs ; margin of scu- 

 tellum rimmed. The pronotum has a few, moderately 

 stout bristles ; the lateral propleuron is densely pilose ; 

 the whole of the mesopleuron is pilose, more densely on 

 the posterior half, and there is extensive pile on the 

 upper sternopleuron, the posterior hypopleuron, the 

 posterior pteropleuron and a wide band of very slender 

 bristles or bristly pile on the metapleuron. Posterior 

 basalare with only weak bristles. The lateral meta- 

 sternum posteriorly and the ventral metastemum are 

 densely, long pilose. Postmetacoxal area membranous. 

 Coxa at most with weak bristles. 



Legs: the femora are comparatively short and stout, 

 bristles of the legs are stout and long. On the hind 

 femur are 6 dorsolateral bristles, the last two forming 

 part of an apical and subapical dorsal, transverse 

 cluster of bristles, and the latter cluster contains 1 lat- 

 eral element. There are 2 ventrolateral bristles and 2 

 stout, apical, dorsomedial bristles. There is a long, 

 basal ventromedial bristle and long hairs on the basal 

 half, and bushy, coarse, black pile on the outer half. 

 The hind basitarsus is rather long, equal to the next 

 three segments; middle basitarsus short and anterior 

 basitarsus intermediate between the two. 



Wings : The wings with characteristic venation ; the 

 third submarginal cell is less narrow than in many spe- 

 cies ; the apex of the anal lobe is moderately extended. 



Abdomen : The abdomen is rather narrow at base and 

 not as wide as the mesonotum, except on the first tergite. 

 Sides of the first three tergites with comparatively long 

 pile. Eighth segment of male long and well developed. 

 Females with only seven tergites not included in the 

 ovipositor, which is sharply and clearly differentiated. 

 Male terminalia exceptionally long and slender with a 

 long, prominent hypandrium wliich appears to be fused 

 laterally to the base of the superior forceps. Gonopod 

 half as long as the forceps, the latter is rather curved, 

 and as they are apposed medially, a large open space is 

 enclosed. The three-part aedeagus extends beyond. 

 Female ovipositor composed of the broad, cylindrical, 

 eighth segment, approxhnately as long as the following 

 two segments but, however, shorter above and longer 

 below; it is strongly compressed except at the base. 

 The ninth and tenth segments are strongly and com- 

 pletely compressed laterally but high, with a sharply 

 pointed apex, but with the halves ventrally flared, and 

 divergent ; tenth segment wedged into the ninth. 



Parapromachus, new subgenus 

 FiGUBES 317, 13S8, 1394 



Type of .subgenus: Promachiis leonhms Loew, 1848. 



Small, rather short, robust flies, characterized by the 

 rather fine, dense pile, more or less appressed on most of 

 the abdomen and the middle of the mesonotum. Length 

 16 to 22 mm. 



Head, lateral aspect : The face is plane ; occiput with- 

 out bristles but with dense, fine pile throughout. An- 

 tenna widely separated and the third segment is com- 

 paratively broad at base and attenuate with a short style 

 which is only slightly thickened at the apex. 



Head, anterior aspect: The face is rather wide and 

 divergent below ; it has no bristles but is densely covered 

 with long, fine pile and with similar, abundant pile on 

 the sides of the front and vertex. The vertex is rather 

 deeply excavated with sloping sides and quite small 

 ocellarium wliich is also pilose. 



Thorax : The mesonotum is rather high, densely cov- 

 ered with rather fine pile, including a broad, anterior 

 medial, longitudinal band of pile which is narrowly dif- 

 ferentiated by a bare stripe on the anterior third of the 

 mesonotiun. Notopleural bristles absent. There are 



1 slender supraalar and 3 postalar bristles. Bristles 

 absent on the scutellum ; its margin and the whole sur- 

 face is densely long, rather fuie pilose. Wliole of the 

 mesopleuron densely pilose as well as the posterior half 

 of the sternopleuron, pteropleuron ancl hypopleuron, the 

 lateral metasternum and nearly the whole of the ventral 

 metasternum. Postmetacoxal area membranous. 



Legs : The femora are unusually short and stout, such 

 bristles as are present are short and stout. The hind 

 femur has 3 dorsolateral bristles and 2 or 3 ventrolateral 

 bristles; 1 bristle of the former group forms part of a 

 transverse, subapical cluster of 3 bristles; and there are 



2 dorsomedial apical bristles. Hind tibia with 1 dorso- 

 lateral distal bristle, absent in the female and 1 ventro- 



