^Etruscan sea creatures, including a range of hippocampi, are set in cultural context and ordered by typology in Monika Boosen, Etruskische Meeresmischwesen: Untersuchungen zur Typologie u. Bedeutung (Archaeologica 59) (Rome:Bretschneider) 1986.
^Katharine Shepard, The Fish-Tailed Monster in Greek and Etruscan Art, 1940, pp 25ff; the thesis was, exceptionally, reviewed (by G.W. Elderkin) in American Journal of Archaeology45.2 (April 1941), pp. 307-308: available on-line through JSTOR.
^Nigella Hillgarth, Birch Aquarium at Scripps Institute of Oceanography, in Myth, Legend & Art, January 8th, 2010 (retrieved Jan 10, 2013)
^Fox-Davies, Arthur Charles. Complete Guide to Heraldry, 1978.
Classical references: Homer, Iliad xlii. 24, 29; Euripides, Andromache 1012; Virgil Georgics iv. 389; Philostratus Imagines i. 8; Statius Thebaid ii. 45 and Achilleid 1.25.