[525]

"Die Entwicklung der Synapta digitata," Jen. Zeitschr. xxii. 1888, p. 175.

[526]

"Die Cambrische Stammgruppe der Echinodermen," Jen. Zeitschr. xxx. 1895.

[527]

Lankester's Treatise on Zoology, "Echinodermata," pt. iii. 1900, p. 33.

[528]

Brit. Mus. Cat. "British Echinodermata," 1892, p. 14.