III. Dinoflagellata: two flagella at least, one parallel to the long axis of the body, the other transverse to it: includes two orders.

1. Adinida: two flagella at anterior pole; a bivalved envelope pierced by pores; Exuviaella, Prorocentrum.

2. Dinifera: one flagellum as a rule turned backwards; one or more transverse flagella lodged in one or more transverse furrows; (i) Peridinidae, with a single transverse furrow at or near the middle of the body; sometimes naked; e. g. Peridi-nium, Ceratium, etc.; (ii) Dinophysidae, transverse furrow single, more or less anterior; a bivalved envelope; e.g. Dinopkysis, Amphidinium; (iii) Poly'dinidae, several transverse furrows; naked; Polykrikos.

IV. Cystoflagellata: protoplasm reticulate, a single flagellum; marine; Nocti-luca, Leptodiscus.

(i) Flagellata. Butschli, Protozoa, Bronn's Klass. u. Ordn. des Thierreichs, i. pp. 620-876; Kent, Manual of Infusoria, i. 1880-81, pp. 216-322, 366-96, 401-38;

1The Chrysomonadina, Chlamydomonadina, and Volvocina are holophytic, and provided with chromatophores. Botanists usually consider them as Algae, and Butschli unites them under the common designation of Phytotnastigoda.

Balbiani, Journ. de Micrographie, Paris, vi. 1882; vii. 1883; viii. 1884; von Stein, Organismus der Infusionsthierchen, Leipzig, iii. (I), 1878.

Various forms: Seligo, 'Untersuchungen,' etc, Cohn's Beitrage zur Biol. der Pflanzen, iv. (2), 1886; Fisch, 'Untersuchungen,' etc., Z. W. Z. xlii. 1885; Klebs, 'Uber die Organisation,' etc., Unters. Bot. Inst. Tubingen, i. 1883; Butschli, 'Beitrage,' etc., Z. W. Z. xxx. 1878. Parasitic forms. Blochmann, 'Bemerkungen,' etc., Z. W. Z. xl. 1884 (with marine Oxyrrhis); Leuckart, 'Parasites of Man,' transl. by Hoyle, Edinburgh, i. 1886, pp. 240-52; Haematozoa, Danilewski, Biol. Centralblatt. v. 1885-6; Mitrophanow, ibid. iii. 1883-4; Danilewski, Archives Slaves de Biol. i. 1886; Crookshank, Journal R. Micr. Soc. (2), vi. 1886; Lewis, Q. J. M. xxiv. 1884; xix. 1879.

Individual forms. Mastigamoeba, F. E. Schulze, A. M. A. xi. 1875, p. 583; Archer, Q. J. M. xvii. p. 530; Butschli, Z. W. Z. xxx. 1878, p. 269. Ciliophrys, Cienkowski, A. M. A. xii. 1876, p. 29; Archer, Q. J. M. xvi. p. 300; Butschli, op. cit. p. 268. Dimorpha, Gruber, Z. W. Z. xxxvi. 1882. Actinomonas, Kent, Manual of Infusoria, i. 1880-1, p. 226. Trypanosoma, Danilewski, Biol. Centralblatt. v. 1885-6, p. 530, and references in Butschli's Protozoa, p. 811. Life-histories, Dal-linger and Drysdale: - a Cercomonad, Monthly Micr. Journal, London, x. 1873; a Bodo (Diplomastix), ibid.; a Bodo (Diplomastix), op. cit. xi. 1874; Oikomonas sp.? s. Monas Dallingeri, ibid.; Polytoma uvella, op. cit. xii. 1874; Tetramitus rostratus, op. cit. xiii. 1875. 'Springing Monad' s. Dallingeria Drysda/i, Dallinger, P. R. S. xxvii. 1878. Polytoma, Krassilstschik, Z. A. v. 1882. Cercobodo, Id. Z. A. ix. 1886. Bodo necator (parasite on Salmonidae), Henneguy, A. Z. Expt. (2), ii. 1884. Astasia ocellata and Englena viridis, Khawkine, A. Sc. N. (6), xix. 1885. Species of Chro-mulina = stages of Palme Ha, Wille, Bot. Centralblatt. xxiii. 1885. Stephanosphaera pluvialis, Hieronymus, Cohn's Beitrage zur Biol, der Pflanzen, iv. (1), 1884. Volvox, Cohn, ibid. i. 1875; V. minor, Kirchner, ibid. iii. (1), 1879; germination of spores of V. dioicus, Henneguy, A. N. H. (5), iii. 1879. Lophomonas, Grassi, Journal R. Micr. Soc. (2), vi. p. 464.

Chromatophores, Sallitt, Q. J. M. xxiv. 1884; Schmitz, Jahrbuch Wiss. Bot. xv. 1884. Haematochrome, von Wittich, Arch, fur Pathol. Anat. xxvii. 1863, p. 573. Influence of light, Butschli, Protozoa, op. cit. p. 861. Thermal death point, Dallinger, Journal R. Micr. Soc. iii. 1880; thermal adaptivity, Id. op. cit. (2), vii. 1887.

(ii) Choanoflagellaia: Butschli, Protozoa, op. cit. supra pp. 877-905; Kent, op. cit. supra, i. pp. 324-65; von Stein, op. cit. supra.

Codosiga botrytis, Fisch, Z. W. Z. xlii. 1885, p. 88; Protospongia (Protero^ spongia) pedicellata, Oxley, Journ. R. Micr. Soc. (2), iv. 18841.

On relationship with Sponges, Schulze, A. N. H. (5), xv. 1885.

(iii) Dinqflagellata: Butschli, op. cit. supra, pp. 906-1029; Kent, op. cit. supra, i. pp. 439-63; von Stein, op. cit. supra, iii. (2), 1883.

Various forms-. Gourret, Annales du Muse'e d'Hist. Nat. Marseille, i. 1883; Bergh, M. J. vii. 1882; Pouchet, Journal de l'Anat. et Physiol. (Robin), xix. 1883; xxi. 1885; xxiii. 1887; Klebs, Unters. Bot. Inst. Tubingen, i. 1883; Id. Bot. Zei-tung, xlii. 1884.

1Saville Kent (op. cit. ii. p. 858) has replaced the generic name Protospongia by Protero-spongia.

Individual forms. Peridinium stygium, Joseph, 'Grotten-Infusorien,' Z. A. ii. 1879, p. 114; Ceratium hirundinella, Blanc, A. N. H. (5), xvi. 1885; Glenodinium cinctum, marine forms, affinities, Biitschli, 'Einige Bemerkungen,' etc, M. J. x. 1885; affinities, etc, Klebs, Biol. Centralblatt. iv. 1884-5.

Fission, Bergh, Zool. Jahrbucher (Spengel), ii. 1886. Phosphorescence, Id. ibid, p. 83.

(iv) Cystoflagellata. Noctiluca, Biitschli, op. cit. supra, p. 1030; Id. M. J. x. 1885, pp. 562-73; Allman, Q. J. M. xii. 1872; Cienkowski, A. M. A. vii. 1871 j ix. 1873; Giglioli, Atti R. Accad. Torino, v. 1870; Pouchet, Journal de l'Anat. et de la Physiol., xix. 1883, pp. 436-8; Robin, ibid. xiv. 1878; von Stein, Organismus der Infusionsthiere, iii. pt. 2, Leipzig, 1883, p. 26; physiology, Vignal, Arch, de Physiol, norm, et pathol. (2), v. 1878. Leptodiscus, R. Hertwig, J. Z. xi. 1877.