Univalve

a. and sb. Nat. Hist. [See UNI- and VALVE sb.¹ Cf. F. univalve (1752), It. and Pg. univalve, It. and Sp. univalvo, mod.L. univalvis.]

  A.  adj. a. Conch. Of mollusks: Having a shell consisting of one valve. Of shells: Composed of a single valve or piece.

1661.  Lovell, Hist. Anim. & Min., A 7 b. Fishes, which … are, turbinate,… bivalve,… or univalve.

1752.  J. Hill, Hist. Anim., 115. The first [series of shellfish] containing those formed of only one piece; this I shall call the simple ones; others have called them univalve ones.

1774.  Phil. Trans., LXV. 46. The smallest univalve or testaceous animal of any such kind.

1816.  W. Smith, Strata Ident., 27. Bivalve shells [are] most common to the thick beds; univalve to the thin.

1851.  G. F. Richardson, Geol., viii. 230. When they have a shell it is thin, fragile, and univalve.

1872.  W. S. Symonds, Rec. Rocks, vi. 181. A univalve mollusk.

  b.  Ent. Having one valve.

  Also in recent use in Zool. and Bot.

1826.  Samouelle, Direct. Collect. Insects & Crust., 54. Proboscis [of Diptera] (rarely wanting) univalve.

  B.  sb. Conch. A univalve mollusk or shell.

1668.  Wilkins, Real Char., 129. Venus Shell … being of near affinity to the Univalvs.

1683.  Phil. Trans., XIV. 507. Distinction of shells into Univalves, Bivalves, and Turbinated.

1755.  Gentl. Mag., XXV. 32/2. When a shell, therefore, is found to be a Univalve.

1785.  Phil. Trans., LXXV. 342. The univalves … have the intestine reflected back.

1832.  Lyell, Princ. Geol., II. 110. Aquatic univalves usually attach their eggs to leaves and sticks.

1854.  Kingsley, Lett. (1878), I. 411. The crevices of the highest rocks … have their peculiar little univalves.

1879.  trans. Semper’s Anin. Life, 41. Animals … as low in the scale as the Amphibia or Univalves.

  Hence Univalved, Univalvular adjs., Bot. having or consisting of one valve.

  Also, in recent Dicts. (1891–), univalvate.

1823.  Crabb, Technol. Dict., *Univalved,… one-valved; an epithet for a pericarp.

1857.  A. Gray, First Less. Bot. (1866), 235. Univalved, a pod of only one piece after dehiscence.

1793.  Martyn, Lang. Bot., Folliculus,… a follicle, a *univalvular pericarp.

1830.  Lindley, Nat. Syst. Bot., 294. Those species of Panicum whose outer flower is univalvular.

1849.  Balfour, Man. Bot., § 530. The pericarp becomes divided into different pieces, which are denominated valves, the fruit being univalvular, bivalvular,… &c. according as there are one, two, or many valves.