WHEAT FLIES — MEROMYZA AND SIPHONELLA. 299 



those of the other groups of the extensive Family MusciDiE in the 

 Order Diptera, by their small size, by having the last joint of 

 their antennae globular insead of oval or oblong; by being desti- 

 tute of winglets, those small scale-like appendages which occur 

 at the base of the wings, having some resemblance in their shape 

 to the bowl of a spoon; and the veins and veinlets of the wings 

 being as they are represented in the accompanying figures. 



One of the prettiest of the flies of this group, which we meet 

 with upon growing wheat the latter part of June, pertains to the 

 genus Meromyza, which is readily known from the other genera, 

 by having the thighs of the hind pair of legs thick and appearing 

 as though they were swelled. It is very similar to the European 

 M. saltatrix Linn., but is larger, the stripes on its thorax are 

 deeper black than those upon its abdomen, and here it is the 

 latter stripes which are united or confluent at their ends and not 

 the former. It may be named 



The American Meromyza, M. Jlmericana. It is 0.17 in length to the tip of its 

 abdomen, and 0.20 to the end of its wings. It is yellowish white with a black spot 

 on the top of its head, which is continued backward to the pedicel of the neck. 

 Thorax with three broad black stripes, approaching each other anteriorly but not 

 coming in contact, the middle stripe prolonged anteriorly to the pedicel of the neck 

 and posteriorly to the apex of the scutel. Abdomen with three broad blackish 

 stripes, which are confluent posteriorly and interrupted at each of the sutures. 

 Tips of the feet and veins of the hyaline wings blackish. Eyes bright green. An- 

 tennae dusky on their upper side. 



Another minute pretty fly, often found wi^th the preceding 

 upon wheat, and resembling it in its colors, is generically dis- 

 tinguished from it by its short, thick body, its abdomen, when 

 distended by a recent meal, being perfectly spherical and ab- 

 ruptly drawn out at its tip into a conical point. The second 

 veinlet of its wings, moreover, is very oblique instead of being 

 transverse as in all the other genera of this group. It thus be- 

 longs to Macquart's genus Siphonella, and the present species 

 may be named in allusion to its plumpness 



The obese Siphonella, S. obesa. It measures only 0.09 in length, to the tip of 

 its abdomen and 0.12 to the end of its wings. It is black and polished, with a slen- 

 der stripe on the middle of the thorax, the scutel and the under side of the body 

 bright sulphur yellow, the abdomen having a tinge of green beneath. Legs bright 

 tawny yellow. Head yellowish white. Antennas tawny yellow, their tips black. 

 Two dots on the anterior edge of the mouth, a large egg-shaped spot on the crown, 

 two short stripes low down on each side of the breast, and the anterior pair of 

 feet, black. 



