Palæont. [ad. mod.L. Trigōnellītēs (given as a generic name), f. mod.L. Trigōnella: see prec. and -ITE1 2 a.] A fossil of triangular form and shelly consistence, found in the Kimmeridge clay; ‘probably the operculum of a cephalopod’ (Lyell).
[1748. J. Hill, Hist. Fossils, 646. That kind [of Cockle] call’d by authors Trigonella…. This kind … approaches to a triangular figure.]
1831. Murchison, in Phillips, Man. Geol. (1855), 301. Hard, compact, not oolitic, containing brachyphyllum, ferns, and trigonellites.
1851. Woodward, Mollusca, I. 80. They were described in 1811, by Parkinson, who called them trigonellites.
1885. Lyell, Elem. Geol., xx. (1885), 295.
