566 



UNITED STATES NATIONAL MUSEUM BULLETIN 224 



is short, pollinose and sunken in the middle ; the lateral 

 fourth of the front has a double row of rather long, 

 slender bristles, the sides divergent. Tlie vertex is nar- 

 rowed and only naoderately excavated ; the rather large, 

 rounded ocellarium is set far forward with 3 or 4 pairs 

 of central bristles and as many others behind. 



Thorax : The mesonotum is rather high ; it is strongly 

 sloping posteriorly and abrupt anteriorly and a little 

 compressed laterally on the anterior half. The pile is 

 erect and setate or bristly, except in front of the posta- 

 lar region. Acrostical elements are undifferentiated; 

 dorsocentral bristles are present and long and stout on 

 the posterior half; humerus bristly pilose. The lateral 

 complement of long, stout bristles consist of: 1 post- 

 humeral, 2 notopleural, 2 supraalar, 1 postsupraalar, 2 

 postalar and 2 to 4 pairs of scutellar bristles. The 

 scutellum is moderately thick and convex; it has im- 

 pressed rim, pollen, and scanty, fine, erect pile. The 

 metanotal callosity is bullose and bristly pilose. Pro- 

 pleuron, upper mesopleuron, stemopleuron, pteropleu- 

 ron all with tufts of long hairs ; tegula pubescent only. 

 The posterior hypopleuron and metapleuron each have 

 a vertical row of bristles. Postmetacoxal area mem- 

 branous ; prosternum dissociated. 



Legs: The femora are stout, the first four slightly 

 swollen basally ; all tibiae likewise are stout ; both are 

 densely appressed, fine setate. Bristles moderately 

 abundant, quite stout and semiblunt. The hind femur 

 bears 2 lateral bristles along the middle, a pair dorsally 

 at the subapex, again at the apex and several weaker 

 bristles ventrolaterally and 1 bristle at the apex. The 

 hind tibia bears stout bristles, 3 dorsolateral, 2 dorso- 

 medial on the basal half, 2 ventrolateral on the distal 

 half and G at the apex. Middle femur with 3 stout 

 lateral bristles in the middle, sometimes a basidorsal 

 element, 2 at apex posteriorly and weaker bristles at 

 the apex anteriorly. Middle tibia with quite weak 

 bristles at the apex anteriorly and posteriorly and a 

 posterodorsal fringe of bristly hairs. Anterior tibia 

 similar to the hind pair. Basitarsus as long as the next 

 two segments. Coxa with lateral bristles. Claws mod- 

 ei-ately sharp, chiefly bent at apex. Puhdlli and 

 empodium large. 



Wings: The marginal cell closed and petiolate, 

 slightly wider in the male at the expense of the sub- 

 costa cell and gently rippled. The second basal cell is 

 a little narrowed in the middle. Second posterior cell 

 at least twice as wide at the base as the end of the discal 

 cell. Fourth posterior and anal cells closed and 

 stalked. Alula large; ambient vein complete. 



Abdomen: In the abdomen only the first tergite is 

 as wide as the mesonotum. The pile of the abdomen 

 is rather scanty, appressed and setate. The stemites 

 bear a few, scattered, long, bristly hairs. Postlateral 

 bristles are well developed on at least the first 4 tergites 

 and less pronounced on the remaining ones. The abdo- 

 men is subcylindrical and slightly tapered. Male with 

 eight tergites, the eighth about half as long as the sev- 

 enth, both medially and laterally. Females with seven 



tergites, those beyond incorporated in the ovipositor. 

 The male terminalia tend to have an elongate, poste- 

 riorly convergent, superior forceps and a much shorter 

 gonopod, together with erect, spatulat« proctiger and 

 a 3-pronged aedeagus. There is a rather conspicuous 

 hypandrium and the eighth sternite is developed into 

 a long, sometimes excised process of varying length. 

 In some species it is distinctly shorter. The female 

 terminalia are remarkably compressed and flattened 

 laterally; the ninth tergite is nearly as long as the 

 eighth, the dorsal proctiger wedged in at apex. 



Distribution: Nearctic: Eutolmus lecythus Walker 

 (1849) [=fe7n.oraIis Macquart (1847]. 



Palaearctic : Eutolmus albiventris Villeneuve 

 (1920); amiulatus Becker (1923); apiculatus Loew 

 (1848) ; apicalis Becker (1913) ; hrevistylus Coquillett 

 (1898); calojms Loew (1848); excisus Loew (1848); 

 facialis Loew (1848) ; graeeiis Loew (1871) ; haemato- 

 scelis Gerstaecker (1861) [ = male stenolabes Loew 

 (1871)] ; immaculatus Loew (1870) ; implacidus Loew 

 (1870) ; kiesenwetteri'Lo&'w (1854)) [=involvilisFiin- 

 delle (1905), hyaloptems Loew (1871), lacteipennis 

 Becker (1923), variipennis Strobl (1909)]; leucacan- 

 ttius Loew (1871) ; lusitanicus Loew (1854) ; mediocris 

 Becker (1923); mordax Loew (1948) [=periscelis 

 Loew (1848)] ; parricida Loew (1848) ; pictipes Loew 

 (1848) ; polypogon Loew (1848) ; rnifibarhis Meigen 

 (1820) ; [^forcipatus major Fallen (1814)] ; sedakoffi 

 Loew (1854) ; simiatus Loew (1854) ; stratiotes Ger- 

 staecker (1861) ; tolmxeroides Bromley (1928) ; ussuri- 

 ens^Engel (1928). 



Melin (1923) describes egg, larva, and pupa of Eu- 

 tohnus rufibarhis. 



It should be noted that Asilus agrarius Walker has 

 been placed in synonymy under Eutolmus lecythus 

 Walker. I have not seen lecythus and can not afiirm 

 the assigimient of this species. 



Genus Dysmachus Loew 



Figures 299, 782, 1532, 1541, 2294, 2317, 2386, 2389 



Dysmachus Loew, Abh. Naturw. Ver. Halle, vol. 2, p. 143, 1860. 

 Type of genus : Asilus trigonus Meigen, 1804. Designated 

 by Coquillett, 1910, the third of four species. 



Small or medium size flies of dull color, character- 

 ized by tlie prominent gibbosity of the face, the strong 

 dorsocentral and acrostical bristles wliich are present 

 anteriorly on the mesonotum and the prominent bristles 

 present on the abdonunal tergites, together with the 

 compressed female terminalia. INIales without any 

 process from the eighth sternite. Tlie eighth tergite is 

 usually hidden medially. Length 12 to 20 mm. 



Head, lateral aspect: The head is rather long, the 

 gibbosity prominent, generally with flat sides laterally 

 and the upper fourth of the face is plane with the eye 

 and micropubescent only. The occiput is prominent, 

 especially below. Lower fourth of eye angularly reces- 

 sive ; the lower half of the occiput is densely long pilose 



