original description
(of Cancellaria (Trigonostoma) agalma Melvill & Standen, 1901) Melvill, J. C. & Standen, R. (1901). The Mollusca of the Persian Gulf, Gulf of Oman and Arabian Seas as evidenced mainly through the collections of Mr. F. W. Townsend, 1893-1900, with descriptions of new species. Part 1, Cephalopoda, Gastropoda, Scaphopoda. <em>Proceedings of the Zoological Society of London.</em> 1901 (2): 327-460., available online at http://biodiversitylibrary.org/page/31888798
page(s): 450, pl. 24, fig. 18. [details]
basis of record
Bosch D.T., Dance S.P., Moolenbeek R.G. & Oliver P.G. (1995) <i>Seashells of eastern Arabia.</i> Dubai: Motivate Publishing. 296 pp.
page(s): 156, fig. 676. [details]
additional source
Hemmen, J. (2007). <i>Recent Cancellariidae. Annotated and illustrated catalogue of Recent Cancellariidae</i>. Privately published, Wiesbaden. 428 pp. [With amendments and corrections taken from Petit R.E. (2012) A critique of, and errata for, <i>Recent Cancellariidae</i> by Jens Hemmen, 2007. <i>Conchologia Ingrata</i> 9: 1-8]. [details]
From editor or global species database