[304] Zool. Anz. 1882, p. 472.
[305] Zoologist, iv. p. 1266.
[306] Journ. Mar. Biol. Ass. N.S. i. p. 217.
[307] Moquin-Tandon, Moll. de France, i. p. 133.
[308] Zool. Jahrb. Anat. iv. (1890) p. 501.
[309] Baudon, Rév. Mag. Zool. 1852, p. 575.
[310] Arch. Zool. Exp. Gén. (2) v. 1887, p. 2; compare also C. H. Hurst, Natural Science, ii. pp. 360, 421.
[311] Compare Pelseneer, Bull. Sci. Fr. Belg. (3) xix. pp. 107, 182.
[312] Pelseneer, Arch. Biol. viii. p. 723.
[313] Also known as labial and supra-oesophageal ganglia.