%lingula%

‖n.; pl. lin"gu*læ [L., a little tongue.] 1. (Anat.) A tonguelike process or part. [1913 Webster]

2. (Zool.) Any one of numerous species of brachiopod shells belonging to the genus Lingula, and related genera. See Brachiopoda, and Illustration in Appendix. [1913 Webster]

Lingula flags (Geol.), a group of strata in the lower Silurian or Cambrian system of Wales, in which some of the layers contain vast numbers of a species of Lingula. [1913 Webster]