[107]

Mitth. Z. Stat. Neapel, x. 1891.

[108]

The most useful works on the Salpidae are Traustedt, Vid. Selsk. Skr. ii. 8, 1885, Copenhagen; and Brooks's "The genus Salpa," Johns Hopkins Biolog. Memoirs, ii. 1893.

[109]

According to Metcalf, Salpa cylindrica is protandrous.

[110]

For a more detailed account of these subdivisions of the Salpidae, and other groups, see Herdman's "Revised Classification of Tunicata," Journ. Linn. Soc., Zool., xxiii. 1891, p. 558.

[111]

See Herdman, Challenger Report on Tunicata, part iii. 1888, p. 88; and Metcalf, Johns Hopkins Univ. Circ. No. 106, 1893, and Zool. Jahrb. Abth. Anat. xiii. 1900, p. 572.