Reeve, L. A. (1856). Monograph of the genus
Spondylus. In:
Conchologia Iconica, or, illustrations of the shells of molluscous animals, vol. 9, pl. 1-18 and unpaginated text. L. Reeve & Co., London. [stated dates: pl. 1-4, January 1856; pl. 5-8, February 1856; pl. 9-14, May 1856; pl. 15-18, June 1856].