E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Trygon.
A poisonous fish. It is said that Telegonos, son of Ulysses by Circ, coming to Ithaca to see his father was denied admission by the servants; whereupon a quarrel ensued, and his father, coming out to see what was the matter, was accidentally struck with his sons arrow, pointed with the bone of a trygon, and died.