[252]

Owen, op. cit. p. 424.

[253]

Macallum, l.c.

[254]

Balfour and Newton Parker, op. cit. p. 425.

[255]

Cuvier and Valenciennes, Hist. Nat. d. Poiss. xix. 1846, p. 151.

[256]

Rathke, Üb. d. Darmkanal u. d. Zeugungsorgane d. Fische, Halle, 1824, pp. 62 f.