. Monographs of the Diptera of North America [microform]. Diptera; Insects; Diptères; Insectes. OKTALID-BâlUVELLIA, 87 markably narrow; tbe small crosssvein is in the middle of tlie diseal cell; the posterior angle of the anal cell is rounded niid the last section of tbe fourth longitudinal vein is parallel to the third, Uah. Cuba (Guudlach). Gen. III. RITELLIA R. Desv. Characl.âFront of equal breaiitli, not projecting in profile. AntfiituB usually reaching down to tli« margin of the mouth; third joint long ai d narrow ; ariiita with a very short pubescHUie. Face ratlj«r txcavated, its lowe
. Monographs of the Diptera of North America [microform]. Diptera; Insects; Diptères; Insectes. OKTALID-BâlUVELLIA, 87 markably narrow; tbe small crosssvein is in the middle of tlie diseal cell; the posterior angle of the anal cell is rounded niid the last section of tbe fourth longitudinal vein is parallel to the third, Uah. Cuba (Guudlach). Gen. III. RITELLIA R. Desv. Characl.âFront of equal breaiitli, not projecting in profile. AntfiituB usually reaching down to tli« margin of the mouth; third joint long ai d narrow ; ariiita with a very short pubescHUie. Face ratlj«r txcavated, its lower part projecting ; the lateral portions very narrow; clypeus broad; occiput moduratuly turgid; eyes high ; cheeks moderately broad. Scuiellurn convex, with four bristles. Wings: Marginal and submargiiial cells comparatively broad ) the second section of the fourth longitudinal vein remarkably sinuate, with the convexity encroaching U[>on the diseal cell, so that the latter appears mui h narrower before the small crossvein than behind it; the last section of the fourth longitudinal vein is parallel to the third vein or very slightly diverging; posterior angle of the cell rounded. A largo number of closely resembling species belong to this genus; the picture oi the wings of most of them is nearly the same, so that this picture alone helps to recognize the species belonging here; it consists of -four brown or blackish-brown rossbands; the first starts from the root of the wing and is the most oblique of all and the shortest; the second, somewhat longer and less oblique, runs over the small crossvein; the third, which covers the posterior crossvein, is perpendicular and reaches from the anterior to the posterior margin of the wing; the fourth starts from the anterior margin, near the origin of the third band, and forms a border along the apex of the wing. The North American fauna seems to abound in these species. The appa- rently total absence of plastie differenc
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectd, booksubjectinsects
