1863 G. Gulliver in Ann. & Mag. Nat. Hist. 12 228 As to a special raphid-cell and cystolith, the article in the 'Micrographic Dictionary' should be consulted.

1907 Bot. Gaz. 43 318 Cystoliths are..absent from the colorless parenchyma, in which only raphids and some long prismatic crystals were noticed.

1968 Taxon 17 17 Raphids are elongated calcium oxalate crystals aggregated into bundles and often occurring in exceptionally large cells which at maturity are dead and filled with mucilage.

1998 Behavioural Processes 43 38/1 Arum is known to contain spicules of calcium oxalate (raphids), tiny sharp needles which stick into the buccal mucosa and cause a painful burning sensation.

1981 Proc. Royal Soc. 1980–81 B. 211 243 The attached species..have often developed a distinct heteropolarity and in some a pronounced heterovalvy (namely the presence of raphid and araphid valves in every cell of Cocconeis).

1989 Proc. Acad. Nat. Sci. Philadelphia 141 251 These and other features are compared with similar structures found in other raphid genera.

1995 C. van den Hoek et al. Algae ix. 139/1 Raphe-bearing (raphid) diatoms, on the other hand, are capable of rapid, autonomous gliding movements.

2005 Harmful Algae 4 1/2 Production of this toxin is currently restricted to evolutionarily advanced, raphid diatoms from the family Bacillariophyceae.