^{page 93 note *} See “Postscript,” page 114.

^{page 95 note *} Oversigt over de fra Danmark og dets nordlige Bilande kjendte Ascidiœ Simplices. Vidensk. Meddel, Nat. For., Kjöbenhavn, 1880, p. 415Google Scholar.

^{page 95 note †} Untersuchungen über die Tunicaten des Adriatischen und Mittelmeeres, Abth. iii. p. 19, Wien, 1877Google Scholar.

^{page 95 note ‡} Cat. Mar. Moll. Northumb. and Durham, Trans. Tynes. Nat. Field Club, vol. i. 1850Google Scholar.

^{page 98 note *} Herdman on British Tunicata, Linn. Soc. Jour., Zool., vol. xv. p. 277Google Scholar.

^{page 98 note †} Herdman, Report upon the Tunicata of the “ Challenger ” Expedition, part i. p. 207.

^{page 99 note *} See Herdman, , “On the ‘ Olfactory Tubercle’ as a Specific Character in Simple Ascidians,” Proc. Roy. Phys. Soc. Edin., vol. vi. session ex. p. 256, 1881Google Scholar.

^{page 100 note *} Urtersuchungen über die Tunicaten des adriatischen Meeres, Abth. ii. Taf. iv. fig. 6, Wien, 1875Google Scholar.

^{page 100 note †} Jour. Linn. Soc., Zool., vol. xv. p. 332Google Scholar.

^{page 100 note ‡} Loc. cit.

^{page 101 note *} In Heller's figure they are about one-fourth, of the breadth of the mesh.

^{page 101 note †} Loc. cit., Taf. v. fig. 8.

^{page 101 note ‡} As will be pointed out in the following description, there are a number of details, especially in the branchial sac, in which these “ Triton ” specimens differ from the accounts of Doliolum denticulatum given by Keferstein and Ehlers (Zoologische Beiträge, 1861) and by Grobben (Arbeiten aus dem Zoolog. Instit. der Univ. Wien, 1882). As, however, they agree with those authors' descriptions in the more important anatomical features, and as they could not be referred to any other known species, I prefer to consider them as a variety of Doliolum denticulatum. It is improbable that they are an undescribed species, since they are apparently so common in the North Atlantic. Doliolum denticulatum is probably rather a variable form.

^{page 101 note §} “Voyage de découvertes de 1'Astrolabe,” Zoologie, T. iii. pt. 2, p. 599; Atlas, Mollusques, pi. lxxxix. figs. 25-28. Paris, 1835.

^{page 101 note ║} “Remarks upon Appendicularia and Doliolium,” &c, Phil. Trans. for 1851, part 2, p. 599, pj. xviii.

^{page 102 note *} “Ueber die Gattung Doliolum,” &c., Archiv für Naturgesehichte, 1852, p. 53Google Scholar.

^{page 102 note †} “Ueber die Entwicklung von Doliolum,” Zeitsehrift für wissensch., Zoologie, 1853, Bd. v. p. 13Google Scholar; and “Ueber die Entwioklungscyclus von Doliolum,” &c, Zeitsehrift für wissensch., Zoologie, 1855, Bd. vii. p. 283Google Scholar.

^{page 102 note ‡} Zoologische Untersuchungen, Heft ii., “Salpen und Verwandte,” Giessen, 1854Google Scholar.

^{page 102 note §} Zoologische Beiträge, iii., “Ueber die Anatomie und Entwickelung von Doliolum,” Leipzig, 1861Google Scholar.

^{page 102 note ║} “Ueber die embryonale Entwicklung des Doliolum,” Zoologischer Anzeiger, iv. No. 92, p. 472, and No. 96, p. 575, 1881Google Scholar; also “Zur Naturgesehichte des Doliolum,” Zoologischer Anzeiger, v. p. 429 and p. 447, 1882Google Scholar.

^{page 102 note ¶} “ Doliolum und sein Generationswechsel,” &c, Arbeiten aus dem Zoolog. Instit. der Univ. Wien, &c, t. iv. h. 2, 1882.

^{page 104 note *} Loc. cit., p. 13, woodcut, and pi, i. fig. 1, wb.

^{page 104 note †} Zoologisehe Beiträge, pi. ix. figs. 1 and 2.

^{page 105 note *} Loc. cit., p. 16.

^{page 105 note †} Loc. cit., p. 57.

^{page 105 note ‡} Loc. cit., p. 16, and pi. i. fig. I.

^{page 102 note §} Grobben has figured a similar arrangement in the case of the asexual forms of the same species (Loc. cit., pi. v. figs. 34, &c).

^{page 106 note *} Possibly the cavity (n.a in the figures) represents merely the opening of the duet from the neural gland into the dorsal tubercle of the Asoidiacea, while the spirals (d.t, in PI. XVIII. fig. 11) indicate the sense-organ, which I believe the dorsal tubercle to have formerly been (see Proe. Roy. Soo. Edin., p. 144, 1882-83.

^{page 107 note *} Loc. cit., p. 9.

^{page 108 note *} Loc. cit., p. 58.

^{page 109 note *} Phil. Trans., 1851.

^{page 109 note †} “Recherches sur une annexe de tube digestif des Tuniciers,” Bulletins de I'Academie Royale de Belgique, 2^me ser. t. xxxix. No. 6, 1875Google Scholar.

^{page 110 note *} Phil. Tram., 1851, part ii. p. 602Google Scholar.

^{page 113 note *} See Forbes, and Hanley, , History of the British Mollusca, vol. i. p. 50, 1853Google Scholar.

^{page 113 note †} See Jour. Linn. Soc., Zool., vol. ix. p. 41Google Scholar.