[272]

Günther, Challenger Reports, "Zool." xxii. 1887, p. 3; Garman, Bull. Mus. Comp. Zool. Camb. Mass. xii. 1885, p. 20.

[273]

Günther, op. cit. p. 545; Newton Parker, op. cit. p. 137.

[274]

Howes, op. cit. p. 393 et seq.

[275]

Graham Kerr, P.Z.S., 1901, ii. p. 484.

[276]

In those Elasmobranchs which have more than five branchial clefts there is a corresponding increase in the number of branchial arches and hemibranchs.