[341] Journ. de Conchyl. xii. p. 3.

[342] T. Scott, Journ. of Conch., 1887, p. 230.

[343] M. de Villepoix, Comptes Rendus, cxiii. p. 317.

[344] Proc. Ac. Nat. Sc. Phil., 1892, p. 350.

[345] Mr. B. B. Woodward has recently pointed out (P. Z. S. 1892, p. 528) a very remarkable method of shell absorption and growth in Velates and certain other Neritidae.

[346] The only exception appears to be Pedipes, while in Cassidula and Scarabus the absorption is partial (Crosse and Fischer, Journ. de Conch. xxx. p. 177 f.).

[347] Strombus and Pteroceras (see Fig. [99], p. 200) exceptionally develop a siphonal notch which is distinct from the anterior canal.

[348] The columella, as distinct from the columella lip, is the solid pillar of shell round which the whorls are coiled (Fig. [177]), the lower, or anterior portion of which alone is usually visible.

[349] J. E. Gray, Phil. Trans. 1833, p. 812.

[350] W. H. Dall, Amer. Journ. Sc. xxxviii. p. 445 f.