W. K. Parker, Phil. Trans. 174, Pt. ii. 1883, p. 411; Huxley, Journ. Anat. and Phys. x. 1876, p. 412; Howes, Trans. Biol. Soc. Liverpool, vi. 1891, p. 122.
Huxley, op. cit. p. 421.
W. K. Parker, Phil. Trans. 174, 1883, pp. 376-405; Ayers and Jackson, Journ. Morph. xvii. 1901, p. 193.
Huxley, P.Z.S. 1876, p. 40, et seq.
Dollo, Bull. Soc. Belge Géol. etc. ix. 1895, p. 110.