^{page 717 note *} Spicilegia Zoologia, fasc. 10, pl. i. fig 16.

^{page 717 note †} Encyclopédie méthodique, pl. lxiii. fig. 11.

^{page 717 note ‡} Mém. du mus. d'hist. nat., t. ii. pl. ii. figs. 9, 10.

^{page 717 note ║} Loc. cit., pl. lxiii. fig. 10.

^{page 717 note ¶} Mémoires sur les animaux sans vertèbres, Pt. ii., fasc 1, p. 87.

^{page 717 note **} Histoire naturelle des animaux sans vertèbres, t. iii. p. 126.

^{page 718 note *} Phil. Trans., 1834, Pt. ii. p. 365.

^{page 718 note †} Wiegmann's Archiv, 2 Bd., 1835, p. 309.

^{page 718 note ‡} Loc. cit., p. 382.

^{page 718 note §} Mém. Inst. France, vol. xviii. p. 217.

^{page 718 note ║} Loc, cit., p. 266.

^{page 719 note *} If the mere fact of the union of individuals, irrespective of the cause of that union, is to be considered an important point, then aggregations of true and undoubted Simple Ascidians of the genera Ascidia and Cynthia must also be considered colonies of Social Ascidians, as they were in the case of Stycla grossularia by Van Beneden in 1847 (Mém. de l'Acad. roy. de Belgique, t. xx.). It is now well known that these aggregations are merely caused by the proximity and the coalescence of the tests, and indicate no relationship whatever between the different individuals.

^{page 719 note †} For an explanation of the true nature of these hair-like processes in the Molgulidæ, see Lacaze-Duthiers, Arch, de Zool. expér. et gén. vol. iii. p. 314 (1874).

^{page 719 note ‡} Müller's Archiv fur Anatomie, 1843, p. 45.

^{page 720 note *} Genera of Recent Molluscs, vol. ii. p. 595.

^{page 720 note †} Klassen und Ordnungen des Thier-Reiclis, B. III. p. 216.

^{page 720 note ‡} Grundzüge der Zoologie, p. 840.

^{page 720 note §} Arch. de Zool. expér. et gén., vol. i. p. 501.

^{page 720 note ║} Loc. cit., p. 603.

^{page 721 note *} “Entwickelung der einfachen Ascidien,” Archiv für Microscopische Anatomic, 1872.