[297]

Hatschek, Arb. Zool. Inst. Wien, iii. 1881, p. 79.

[298]

Fraipont, "Le Genre Polygordius," Fauna u. Flora des Golfes v. Neapel, Monogr. xiv. 1887.

[299]

T. J. Parker, Lessons in Elementary Biology, London, 1891, p. 267, gives a full account of the anatomy and development of Polygordius.

[300]

"Die Capitelliden," Fauna u. Flora d. Golfes v. Neapel, Monogr. xvi. 1887, p. 350.

[301]

Encyclopaedia Britannica, 9th ed., Art. "Mollusca," p. 652.