Upper field: in tegmina, = anal field; q.v.
Upper margin: of tegmina (Thomas), corresponds to the posterior or anal margin of most authors.
Upper median area: see areola.
Upper radial: in Lepidoptera, = media 1 (Comst.), and is vein 5, or the independent, of the numerical series.
Upper sector of triangle: in Odonata, = cubitus 1 (Comst.).
Upper Sonoran faunal area: that arid part of upper austral west of 100th meridian; covers most of plains in eastern Montana and Wyoming, s. w. South Dakota, west. Nebraska, Kansas, Oklahoma and Texas, and east. Colorado and New Mexico; covers plains of Columbia, Malheur and Harney in Oregon and Washington. In California encircles Sacramento and San Joaquin Valleys and forms a narrow belt around Colorado and Mohave deserts. In Utah covers Salt Lake and Sevier deserts. In Idaho the Snake plains. In Nevada and Arizona irregular areas of suitable elevation.
Uranidin: a yellow coloring matter in some Coleoptera and Lepidoptera.
Urceolate: pitcher-shaped; swelling in the middle.
Ureter: the stalk connecting the malpighian tubules, when they form large tufts, with the intestine.
Uric acid: the characteristic nitrogenous excretion of the malpighian or urinary tubules: composition, C5H4N4O3 (von Furth).