diurna

pl. [Neut.pl. of Lat. diurnus =per taining to a day, daily; by day, as opposed to by night.] 1. Entom .: The name given by Latreille, Cuvier, and their succe ors to the highest sub-order or tribe of the order Lepidoptera. The term implies that they are day-fliers, as distinguished from the Crepuscular i a, which fly by twilight, and the Nocturn a, which do so by night. The first of these three sub-orders contains the Butterflies; the second the Sphingides, Sphinxes, or Hawk Moths; and the third the Moths, properly so called. The Diurna are placed in harmony with the conditions of their existence, in being clad, as they are, in bright colors. The antenne are knobbed, whence they are often called Rhopalocera (q. v.), the two other suborders being reduced to one, Heterocera. The wings, when in repose, usually stand erect. The caterpillars have six thoracic legs and ten prolegs, sixteen in all. The chrysalides, which, as a rule, angular, are naked, and often suspended head downward. Butterflies are diffused over all countries, but the largest and finest are from the tropics. They may be divided into four families: Papilio nide, Nymphal ide, Lycænide or Polyommatide, and Hesperide (q. v.). "Beasts fain would sing; birds ditty to their notes." Herbert: Providence, st. 3. dit-ty-ing, pr. par., a. & s. [DITTY, v.] A. & B. As pr. par. & particip. adj.: (See the verb.) C. As subst.: The act of singing or warbling; a ditty. "The under-song unto your cheerful dittying ." Fletcher: Purple Island , c. i. di-üre-ideş, s. pl . [Pref. ai =twice, twofold; Eng., ., urea , and Gr. eidos =form, appearance.] Chem.: Organic compounds formed by the union of one molecule of a bibasic acid and two molecules of urea; with elimination of four molecules of water they contain four or five atoms of carbon, as uric acid (q. v.). Diureides containing six and eight carbon atoms are formed by the union of two mon ureide molecules with elimination of water, as alloxan tin (q. v.).