Holt, "On the Breeding of the Dragonet (Callionymus lyra)," P.Z.S. 1898, p. 281.
Howes, Linn. Soc. Journ. Zool. xxiii. 1891, p. 539, where references are given to the literature of the subject.
The American Hags probably belong to a distinct species, M. limosa Girard; Bashford Dean, Science (N.S.), xvii. 1903, p. 433.
Bashford Dean, Kupffer's "Festschrift," Jena, 1809, p. 227 et seq.
Journ. Morph. xvii. 1898, p. 213.