From all points of view both the phylactolæmata and the ctenostomes of Asia have been generally neglected, except in the case of the Japanese phylactolæmata, which have been studied by Oka. Although Carter made some important discoveries as regards the Indian forms, he did not devote to them the same attention as he did to the sponges. In the case of the only new genus he described he introduced a serious error into the study of the two groups by placing _Hislopia_ among the cheilostomes, instead of in its true position as the type genus of a highly specialized family of ctenostomes. For fuller details as to the history of the study of the freshwater Polyzoa the student may refer to Allman's and to Kraepelin's monographs. An excellent summary is given by Harmer in his chapter on the freshwater Polyzoa in vol. ii. of the Cambridge Natural History; and Loppens has recently (1908) published in the Annales de Biologie lacustre a concise survey of the systematic work that has recently been undertaken. Unfortunately he perpetuates Carter's error as regards the position of _Hislopia_. BIBLIOGRAPHY OF THE FRESHWATER POLYZOA. A very full bibliography of the freshwater Polyzoa will be found in pt. i. of Kraepelin's "Die Deutschen Süsswasserbryozoen" (1887), while Loppens, in his survey of the known species (Ann. Biol. lacustre, ii, 1908), gives some recent references. The following list contains the titles of some of the more important works of reference, of memoirs on special points such as reproduction and of papers that have a special reference to Asiatic species. Only the last section is in any way complete. (a) _Works of Reference._ 1847. VAN BENEDEN, "Recherches sur les Bryozoaires fluviatiles de Belgique," Mém. Ac. Roy. Belgique, xxi. 1850. DUMORTIER and VAN BENEDEN, "Histoire Naturelle des Polypes composés d'eau douce," 2^e partie, Mém. Ac. Roy. Bruxelles, xvi (complément). 1856. ALLMAN, "A Monograph of the Fresh-Water Polyzoa" (London). 1866-1868. HYATT, "Observations on Polyzoa, suborder Phylactolæmata," Comm. Essex Inst. iv, p. 197, v, p. 97. 1880. HINCKS, "A History of the British Marine Polyzoa." 1885. JULLIEN, "Monographie des Bryozoaires d'eau douce," Bull. Soc. zool. France, x, p. 91. 1887 & 1892. KRAEPELIN, "Die deutschen Süsswasserbryozoen," Abhandl. Nat. Vereins Hamburg, x & xii. 1890. BRAEM, "Untersuchungen des Bryozoen des süssen Wassers," Bibl. Zool. ii, Heft 6 (Cassel). 1896. HARMER, Cambridge Natural History, ii, Polyzoa, chap. xviii. 1899. KORSCHELT and HEIDER, "Embryology of Invertebrates," vol. ii, chap. xvi. (English edition by Bernard and Woodward, 1899.) 1908. LOPPENS, "Les Bryozoaires d'eau douce," Ann. Biol. lacustre, iii. p. 141. (b) _Special Works on Embryology, etc._ 1875. NITSCHE, "Beiträge zur Kenntniss der Bryozoen," Zeitschr. f. wiss. Zool. xxv (supplement), p. 343. 1880. REINHARD, "Zur Kenntniss der Süsswasser-Bryozoen," Zool. Anz. iii, p. 208.