VI. Subfam. Eurychoromyinae. Eurychoromyia n.gen., an isolated group of acalyptrate muscids.

The head is transversely broadened like in Achias (fig 5 and 8), broader than the length of the dorsum of the thorax including the scutellum, and 5/3 times as broad as high. Viewed from above it has the shape of a crescent with rtex. It corresponds to the ocellar plate, and extends tapering to the anterior rim of the front. The much broader lateral plates cover the entire area up tothe rim of the eyes and are at their inner and anterior borders weakly but distinctly arched.

Between the front above and the likewise chitinised lower face below, a soft, dull, and slightly depressed streak is inserted, generating a transverse separation that extends from one eye to the other. I believe that this streak is a functintirely bare, lacking hairs or bristles, smoothly shining and chitinised and actually longitudinally divided into three parts. The middle part, bearing on its very top at the vertex the three closely spaced ocelli, is a continuation of the cerebral from the vertex. It corresponds to the ocellar plate, and extends tapering to the anterior rim of the front. The much broader lateral plates cover the entire area up to the rim of the eyes and are at their inner and anterior borders weakly but distinctly arched.

Between the front above and the likewise chitinised lower face below, a soft, dull, and slightly depressed streak is inserted, generating a transverse separation that extends from one eye to the other. I believe that this streak is a functional substitute for the otherwise normally occurring streak of the front. Of the ptilinal fissure only a short span is discernible above the bases of the antennae. However, immediately above this there is also already a narrow streak visible, which in the middle slightly penetrates the anterior rim of the ocellar plate, while at the sides it first widens suddenly and then, tapering gradually, rises to the lower corner of the ocellar triangle. Into each of these two lateral parts of the streak one of the branches of the ptilinal fissures merges, without first descending and then running into the groove of the gena (mediana R. D.) below the eye, as is usually the case.

The distance between the antennal bases equals about 1/4 of the anterior width of the front, and this is also the width of the top of the clypeus, which lies at the same level and curvature with the neighboring cheeks and genae. The clearly discernible facial ridges run as straight slightly diverging lines to the corners of the almost horizontal mouth rim, which are formed by the slightly bulging protrusion of the bare cheek-ridges. The curvature of the entire lower face is weak and uniform in transverse direction. Only in longitudinal direction it is interrupted in the profile of the clypeus by shallow protuberances, however, not equally distinct in all specimens.

The antennae are stretched out anteriorly and short. The first segment is clearly visible, yes even longer than the second, which bears an erect bristle above. The third segment is longitudinally oval and about twice as long as wide. The basal arista is slightly thicker at its base and delicately pubescent along its basal half. The prelabrum is narrow, but rather high and clearly visible when viewed from the front or in profile. The palpes do not reach the rim of the mouth with their tips, they are short and filiform, weakly bristled. The proboscis is rather voluminous and has broad labellae which are folded back.

The thorax is almost bullet-shaped through the even curvature of its dorsum and pleurae. The dorsum is square, even slightly shorter than long. It has in its middle two depressed longitudinal lines, which are shortened anteriorly and posteriorly, and are met laterally by the branches of the transverse suture, which are rising vertically slightly in front of the middle of the thorax. The scutellum is broad and short, only 1/4 as long as the dorsum, bulging and very blunt. The pleurae are strongly shortened longitudinally, especially in the anterior half, and are depressed barely discernible in the vicinity of the spiracle above the front coxae. Very peculiar appears the position of the mesopleural suture anterior to the middle of the thorax, and moreover, that the mesopleurae are higher than long and that the thorax is not lowered at the middle- and hind-coxae below the lower end of the front coxae, but conversely appears slightly elevated.

While the head has no bristles at all, on the thorax hair-formed bristles can be determined as 2 notopleurals, 1 dorsocentral, 4 scutellar, and 1 distinct sternopleural bristle. The mesopleural suture also bears small hairs. The abdomen (female) is very broad egg-shaped, dorso-ventrally compressed and composed of 7 visible segments. The seventh segment is narrow protrudes only slightly [from the sixth segment]. The tergites extend with broad rims onto the ventral side, covering 2/3rds of the latter. In the remaining gap very narrow sternites are visible, surrounded by membrane. Only the last three sternites abut the tergites. Behind the seventh segment one sees the two cerci of the end segment protrude above and the similarly shaped and bristled lower [ovipositing hatch] ovipositor below.

The legs are of average length and thickness. All tibiae, especially the middle, and even more the hind tibiae, are strongly compressed laterally and widened in the shape of a circle segment. Their inner rim is straight, their outer rim curved. Only the front tarsi are longer than the tibiae, the two hind ones are only 2/3 as long as the same [tibiae]. Nowhere a distinct bristle or spine is seen. The front coxae have normal shape and size, the hind ones are relatively very short and globular. The femora are straight and gradually thickened towards their tips. The wing shape and venation is best visible from figure 6. The costa is straight, nowhere interrupted or bent, and extends to the end of the discoidalis. The mediastina is completely separate and strong. The subcosta is bare even at strongest magnification. The anal cell is distally closed by a straight cross vein, the anal vein does not reach the wing margin.

According to the first impression that the fly gives, one might think above all of an Ortalidine in a broader sense. The lack of preapical bristles at the tibiae, the general chaetotaxy, the wing venation, and other characters, would allow such an interpretation, especially as in this group of muscids very often bizarre head shapes can be observed, if not the most important character - the threepartite, sclerotized tubular ovipositor of the female was lacking here. The formation of the female abdomen, however, deviates so far from a tubular ovipositor, that the group of acalyptrates equipped with a sclerotized ovipositor, such as Ortalidines, Thephritines, Lonchaeines, can not be considered. On the other hand, the ovipositing apparatus of Eurychoromyia also hints towards the Sciomyzines and Tetanocerines. Moreover, also the short ptilinal fissure, the little specified organization of the lower face, the shallow facials, and so on, the lacking of vibrissae, and partially the strong development of the ocellar plate, constitute shared characters with this group. But because the Sciomyzines possess distinct preapical bristles and an entire circle of spines at the ends of the middle tibiae, whereas Eurychoromyia on the other hand exhibits several peculiarities that do not occur in Sciomyzines, I can not force our genus in here either. The recognition of the systematic affiliation is rendered more difficult especially by the sparse presence of bristles on the new animal. Head bristles are lacking entirely, thoracic bristles almost entirely. Besides that, we know so little of the relationships of the different acalyptrate groups and the actually informative characters and their application for the generation of natural groups, and almost nothing about their biology, that momentarily it appears to me most useful to maintain the genus Eurochoromyia in its isolation. Would I assign it in unnatural manner to one of the existing groups, then I would endanger it not to be recognized by any of the subsequent dipterists.

The most special peculiarity of the new genus is the soft-skinned ribbon- shaped streak that extends transversely above the antennae from one eye to the other, with the unusually short ptilinal fissure running into it. None of the acalyptrate groups known so far has such a streak.

Head, thorax and abdomen shiny pitch-brown, legs likewise. The latter, however, slightly reddish transparent and with broadly yellow bases of the basal tarsal segments of the two posterior pairs of legs. First antennal segment light brown, the others black-brown. The curved cross streak below the front is dull velvety black. The front area also often has a reddish shine. The pattern of the cheeks depicted in figures 5 and 8 is produced by golden tomentosity and simulates transverse wrinkles. The pitch-brown clypeus is also rather strongly tomentose; however, its pattern below the antennae is dull black and is not caused by the basic color.

The pleurae are only very weakly tomentose. The lateral rims of the 3rd and subsequent tergites are above and below punctated by rows of light yellow tomentose spots.

The wings are tinged smoke brown rather intensely and uniformly, only at the base and in the subcostal cell distinctly darker. The veins are dark, the calypteres blackish and likewise long ciliate, the halteres light red-yellow. Body and wings 5 mm long; head 2.5 mm broad.