_Embryologische Studien an Medusen_ (Vienna, 1886), 150 pp., 12 pls., 10 figs.; 45. "Medusologische Mittheilungen," _Arb. zool. Inst. Wien_, vi. (1886), pp. 237-266, pls. xxii. xxiii.; 46. L. Murbach, "Beiträge zur Kenntnis der Anatomie und Entwickelung der Nesselorgane der Hydroiden," _Arch. f. Naturgesch._ lx. i. (1894), pp. 217-254, pl. xii.; 47. "Preliminary Note on the Life-History of _Gonionemus_," _Journ. Morph._ xi. (1895), pp. 493-496; 48. L. Murbach and C. Shearer, "On Medusae from the Coast of British Columbia and Alaska," _Proc. Zool. Soc._ (1903), ii. pp. 164-191, pls. xvii.-xxii.; 49. H. F. Perkins, "The Development of _Gonionema murbachii_," _Proc. Acad. Nat. Sci. Philadelphia_ (1902), pp. 750-790, pls. xxxi-xxxiv.; 50. F. Schaudinn, "Über Haleremita cumulans, n. g. n. sp., einen marinen Hydroidpolypen," _SB. Ges. natforsch. Freunde Berlin_ (1894), pp. 226-234, 8 figs.; 51. F. E. Schulze, "On the Structure and Arrangement of the Soft Parts in _Euplectella aspergillum_" (_Amphibrachium_), _Tr. R. Soc. Edinburgh_, xxix. (1880), pp. 661-673, pl. xvii.; 52. O. Seeliger, "Über das Verhalten der Keimblätter bei der Knospung der Cölenteraten," _Zeitschr. f. wiss. Zool._ lviii. (1894), pp. 152-188, pls. vii.-ix.; 53. W. B. Spencer, "A new Family of Hydroidea (_Clathrozoon_), together with a description of the Structure of a new Species of _Plumularia_," _Trans. Roy. Soc. Victoria_ (1890), pp. 121-140, 7 pls.; 54. M. Ussow, "A new Form of Fresh-water Coelenterate" (_Polypodium_), _Ann. Mag. Nat. Hist._ (5) xviii. (1886), pp. 110-124, pl. iv.; 55. E. Vanhöffen, "Versuch einer natürlichen Gruppierung der Anthomedusen," _Zool. Anzeiger_, xiv. (1891), pp. 439-446; 56. C. Viguier, "Études sur les animaux inférieurs de la baie d'Alger" (_Tetraplatia_), _Arch. Zool. Exp. Gen._ viii. (1890), pp. 101-142, pls. vii.-ix.; 57. J. Wagner, "Recherches sur l'organisation de Monobrachium parasiticum Méréjk," _Arch. biol._ x. (1890), pp. 273-309, pls. viii. ix.; 58. A. Weismann, _Die Entstehung der Sexualzellen bei den Hydromedusen_ (Jena, 1883); 59. R. Woltereck, "Beiträge zur Ontogenie und Ableitung des Siphonophorenstocks," _Zeitschr. f. wiss. Zool._ lxxxii. (1905), pp. 611-637, 21 text-figs.; 60. J. Wulfert, "Die Embryonalentwickelung von Gonothyraea loveni Allm.," _Zeitschr. f. wiss. Zool._ lxxi. (1902), pp. 296-326, pls. xvi.-xviii. (E. A. M.) FOOTNOTES: [1] In some cases hydroids have been reared in aquaria from ova of medusae, but these hydroids have not yet been found in the sea (Browne [10 a]). [2] The numbers in square brackets [] refer to the bibliography at the end of this article; but when the number is preceded by the word Hydrozoa, it refers to the bibliography at the end of the article HYDROZOA.