[485]

"Ueber die Function der Polischen Blasen am Kauapparat der regulären Seeigel," Mitth. Zool. Stat. Neapel, xii. 1897, p. 464.

[486]

Ergebnisse naturwissenschaftlicher Forschungen auf Ceylon, 1887-1888, Bd. i. Heft 3, pp. 105 et seq.

[487]

"Das angebliche Excretionsorgan der Seeigel," Zeitschr. wiss. Zool. lv. 1893, p. 585.

[488]

In this case the fluid flows from the lantern coelom into Stewart's organs and vice versa. Oxygen must be absorbed through the peristome. The Cidaridae are not as sensitive to want of oxygen as the other families (Uexküll, loc. cit.).

[489]

Danish Ingolf Expedition, "Echinoidea," pt. i. 1903.