Stud. Johns Hopkins Univ. vol. iv. 1887-90, p. 389.

[483]

Selenka, Challenger Reports, vol. xiii. 1885.

[484]

Ann. Sci. nat. (7) vol. xx. 1895, p. 1.

[485]

Zool. Anz. ix. 1886, p. 574.

[486]

This is not true of all species.

[487]