[L. ligula strap, spoon, by-form of lingula, f. lingua tongue.]
1. A narrow tongue-like strip or fillet.
a. Bot. A narrow strap-shaped part in a plant, as the ‘limb’ of a ray floret in composite flowers, a projection from the top of a leaf-sheath in grasses, ‘an appendage at the base of some forms of Corona’ (Henslow, 1856). b. Ent. (a) The ‘tongue’ of Crustaceans, Arachnids, and Insects, being a horny, membranous, or fleshy anterior part of the labium. (b) A tongue-like process on the elytra of certain aquatic beetles (Cent. Dict.). c. Anat. ‘A thin lamina occupying the angle between the cerebellum and the restiform body’ (Syd. Soc. Lex., 1888).
a. 1760. J. Lee, Introd. Bot., I. xix. (1765), 50. Ligula, a narrow Tongue, or Fillet.
1845. Lindley, Sch. Bot., i. (1858), 10. [In grasses] there is often a thin membrane called a ligula, at the upper end of the sheath.
1876. Harley, Mat. Med. (ed. 6), 371. Narrow leaves, with a long slit sheath and stipules adherent, forming a membranous ligula.
1882. Vines, Sachs’ Bot., 392. Lycopodiaceæ…. The leaves have no ligula.
b. 1826. Kirby & Sp., Entomol., III. 363. Ligula, a capillary instrument between the lancets; probably representing the tongue of the perfect mouth.
1828. Stark, Elem. Nat. Hist., II. 218. The labium … is formed of two parts; one inferior … is the chin (mentum), the other membranous [etc.] … is termed ligula.
1834. H. M’Murtrie, Cuvier’s Anim. Kingd., 424. Their antennæ are always geniculate, and the ligula is small, rounded and concave, or cochleariform.
c. 1848. Quain’s Anat. (ed. 5), II. 724. The diverging posterior pyramids and restiform bodies surmounted along their margin by a band of nervous substance called the ligula.
2. A genus of cestoid worms, typical of the family Ligulidæ; a worm of this genus.
1840. E. Blyth, etc. Cuvier’s Anim. Kingd. (1849), 649. The fourth Family of the Parenchymata—the Cestoidea—consists of only a single genus,—Ligula. These are the simplest in their organization of all the Entozoa.
1876. Beneden’s Anim. Parasites, Introd. When Rudolphi spoke of the ligulæ of fishes which could continue to live in birds.
3. A genus of mollusks (Cent. Dict.).
1839. Sowerby, Conch. Man., 56.
