34 



UNITED STATES NATIONAL MUSEUM BULLETIN 224 



Distribution: Nearctic: Myelaphus lobicornis Osten 

 Sacken (1877) ; melas Bigot (1882) ; rufus Williston 

 (1884). 



Palaearctic. Myelaphus dispar Loew (1873) ; jo- 

 zanus Matsumura (1916). 



Hermannella, new genus 

 Figuees 11, 421, 845, 854 



Type of genus : Hermannella engeli, new species. 



A rather small fly characterized by the unusually long 

 head and the long, greatly flattened antenna carrying 

 two wide, flattened microsegments. It appears to be 

 related to Scylaticus Loew. It is distinguished from 

 Scylaticus by the very short proboscis and unusual an- 

 tenna ; and from Myelaphus Bigot by the greatly -wid- 

 ened vertex, as well as the not cleft microsegments. 

 Length 12 mm. including antenna. 



Head, lateral aspect : The head is unusually long and 

 subglobular. The face rather long throughout its 

 length, not quite straight in profile, but rather strongly 

 retreating below the antenna. The eye is exceptionally 

 long and strongly convex posteriorly as well as an- 

 teriorly. Occiput unusually tumid and thick through- 

 out, following the eye in its curvature and with a slight 

 thickening or bulge at the margin of the eye. Pile of 

 occiput stiff, short and scanty through the middle, some- 

 what longer above and absent ventrally; all this pile 

 partakes of the character of weak bristles. Proboscis 

 exceptionally short, not or scarcely projecting beyond 

 the face. It is dorsoventrally compressed but with 

 bluntly rounded apex, and bears no ventral basal pile 

 and only 2 or 3 fine hairs ventrally near the middle. 

 Palpus short, cylindrical, with some apical bristly hair 

 and the second segment more slender, distinctly attenu- 

 ate, and apparently without pile or bristles. A small 

 apical pore appears to be present. The basal segment 

 is hemicylindrical and excavated at least on its basal 

 half. Antenna attached at the upper sixth of the head 

 and unusually elongate. The first segment is 3Vo times 

 as long as the short beadlike second segment and is some- 

 what swollen below and subapically. The third seg- 

 ment is subquadrate basally with sharply angular 

 margin dorsally and becomes quite strongly compressed 

 laterally especially along the dorsal margin. The ven- 

 tral margin remains a little wider. The third segment 

 is gently widened on the apical half, somewhat curved 

 upward and laterally. If the apical subsegments are 

 excluded, then the third segment is 2^2 times as long as 

 the first segment. The third segment bears two com- 

 pressed subsegments, each of about equal length and 

 height. The second subsegment has a lateral apical 

 notch and between the ventral and lower portion of this 

 notch there is a minute spine. First antennal segment 

 with numerous, long stiff hairs ventrally, shorter ones 

 laterally and dorsally, the second segment with a few 

 minute lateral and dorsal setae. 



Head, anterior aspect: The face below the antenna 

 is a little less than one-third the head width; it has 



parallel sides. The front is quite strongly divergent, 

 the width at vertex more than two-thirds the head 

 width. Subepistomal area small, horizontal, concave. 

 Face micropubescent, everywhere covered, except at the 

 immediate eye margin, with moderately long, stiff pile ; 

 bristles absent. Front extremely wide but short; on 

 the lateral third there is a conspicuous tuft of moder- 

 ately long bristly hairs. The vertex is not excavated, 

 the ocellarium large, wide, moderately high and bear- 

 ing three or four pairs of slender bristles across the 

 middle. Anterior eye facets slightly enlarged. 



Thorax : The thorax is pollinose, the mesonotum of 

 moderate height. Pile of mesonotum abundant, fine 

 and erect and continuous across the mesonotum. 

 Acrosticals are not or very poorly differentiated, 

 dorsocentral bristles absent; humerus with stiff pile. 

 The lateral mesonotum has the following complement 

 of short, weak, slender bristles : 2 notopleural, 2 supra- 

 alar, 2 postalar ; the strongly flattened scutellum with 6 

 pairs of comparatively short, stiff hairs; the somewhat 

 wrinkled scutellar disc is without pile. The pro- 

 pleuron has only scanty, stiff hairs ventrally and weak 

 bristly hairs posterolaterally ; the anterior collar has 4 

 or 5 pairs of moderately stout bristles; the sterno- 

 pleuron, pteropleuron and hypopleuron apilose ; meta- 

 pleuron with a vertical row of 5 or 6 short bristles. 

 The metanotal slopes are micropubescent only ; lateral 

 metasternum long pilose, the ventral metasternum 

 without pile, the postmetacoxal area membranous; 

 basalare with fine long hairs. 



Legs : The legs are densely, coarsely appressed setate, 

 dorsally and laterally on the femora. All the femora 

 are stout without being thickened. On the hind femur 

 is the following complement of bristles: 5 or 6 weak 

 slender lateral, 7 or 8 weak ventrolateral, and some 

 short weak ventromedial; the hind tibia has 8 short, 

 weak dorsal bristles, 5 similar lateral, and 3 to 5 similar 

 ventrolateral. The middle femur has 3 slender bristles 

 posteroapically, its tibia has 5 or 6 slender bristly hairs 

 dorsally and 7 or 8 equally slender but longer elements 

 posteriorly, besides 3 or 4 short bristly hairs antero- 

 ventrally. Anterior tibia similar to the middle tibia ; 

 the dorsal and posteroventral bristles as weak or more 

 weakly developed and lacking an apical spine; the 

 anterior femora with only short stiff pile. Anterior 

 basitarsus fully as long as the next 3 segments; claws 

 sharp ; the pulvillus well developed ; the empodium long 

 and slender. 



Wings: Marginal cell widely open, the anterior 

 branch of the third vein is sinuous or sigmoid, ending 

 just before the wing apex. First and second posterior 

 cells widely open, fourth open but strongly narrowed, 

 anal cell closed with a short stalk; the alula short and 

 hemicircular in outline; ambient vein complete. 



Abdomen : The abdomen is comparatively robust, not 

 quite as wide as the mesonotum and slightly narrowed 

 at the end of the second tergite. There are 7 tergites 

 in the male, the seventh is two-thirds as long as the 

 sixth. Pile of the abdomen rather scanty, subap- 

 pressed and setate but long and abundant on the sides of 



