This paper deals with a revision of Japanese species of some Turridae such as Gemmula, Turris, and allies, with special reference to the phylogeny of this group. The taxa, the Tribe Turrini in this paper, is the subfamily Turrinae from the reports of POWELL, 1942 and 1964, because his Turrinae, Turriculinae, Cochlespirinae, Clavatulinae, Clavinae, etc. are generally very close compared with Cytharinae and Daphnellinae in the shell features and lingular characters. Turrini is to be divided into three subdivisions with representative genera Kuroshioturris, Gemmula and Turris. Kuroshioturris- and Turris-groups consist of only a single genus from Japanese seas, while Gemmula-group contains Lophioturris, Lophiotoma and Xenoturris. Kuroshioturris and Turris have smooth, paucispiral protoconch, while Gemmula-group has a multispiral (or paucispiral) protoconch with axial riblets on the last turn (or turns). The peripheral keel of Kuroshioturris- and Gemmula-groups is developed on the middle part of the whorl. Turris-group differs from these two, and suprasutural keel of the younger whorls develops to the peripheral on the later whorls, though the peripheral keel of few forms of this group does not well develop and spiral cords are subequal. The earliest part of the teleoconch of Kuroshioturris-group lacks subsutural and suprasutural keels, but, at least, subsutural keel is to be seen in other groups. In the Turris-group three (rarely four) spiral cords are subequal on the younger whorls, and the forms without strong peripheral keel have four subequal spirals on the adult whorls. The radula of the genera Turris and Gemmula are subequal and consists of marginals only, while that of Kuroshioturris is unknown. A new genus Protogemmula is proposed in this paper in order to discuss phylogeny. Protogemmula has small shell with four smooth whorls and a row of granule on the middle part of a whorl instead of peripheral keel. Its type-species is "Gemmula" cretacea SOHD, which is the oldest form of Turrini. Kuroshioturris must be a series of Cretaceous Protogemmula and Campylacrum, Paleogene Eopleurotoma, and living Lucerapex. These genera have smooth protoconch and similar sculpture. Many species of Gemmula group have been reported from Paleogene, but few of them agree with Ptychosyrinx in its features. Ptychosyrinx has short canal, three rowed radula, and multispiral protoconch containing two or more axially ribbed whorls. It is not impossible that Paleogene forms of Gemmula group (Ptychosyrinx) had derived from series of Protogemmula to Kuroshioturris, though a careful revision should be necessary to make sure. Turris-group must have branched from Gemmula group because of the similar characters but for peripheral keel and protoconch.

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Hydrobia totteni (=Hydrobia minuta) is considered a distinct species and not synonymous with the European species Hydrobia ventrosa. Of the European species of Hydrobia, H. totteni is most closely related to H. ventrosa on the basis of penial structure, dorsal head pigmentation and radula formula. The species is considered distinct in that it has fewer rows of teeth on the shorter and narrower radula. H. totteni has a hypertrophy of the cilia on the left tentacle not shown for H. ventrosa. The tentacles of the former have distinct pigment spots which are not well defined in the latter. There is an apparent difference in structure of the basal process of the central tooth. Hydrobia totteni has fewer cusps on the marginal teeth than H. ventrosa. Other structures not studied or compared but of value for specific observation are the female reproductive system and nervous system. The paper deals at length with the morphological description of the common American East Coast species. Noted throughout are features distinguishing this species as a representative of the subfamily Hydrobiinae from genera of the subfamily Pomatiopsinae as the latter was defined by STIMPSON (1865) and DAVIS (1965).

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The present study was undertaken to clarify the filtering rate and digestibility of the freshwater mussel, Hyriopsis schlegelii, with the crude silicate as an indicator. The observations were made in Lake Biwa during the water temperature 5.5-22.7℃. The results obtained were as follows : 1) Approximate estimation of filtering rate from crude silicate method was 4.3∿15.8 l/one mussel/one day. 2) The filtering rate increases according as the water temperature increases. 3) The feeding rate (as dry matter) ranges from 78.7∿361.2 mg/one mussel/one day. 4) The digestibility was 45% (range from 34∿66%).

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The present report deals with the result of observation on sexual behaviour, spawning and hatching of a Clausiliid, Tyrannophaedusa mikado, which was collected from Mt. Kinsho, Gifu Prefecture, and has been reared in petri dish for several years. 1. In copulation, the male inserts its penis into the genital opening of the mate. Mutual insertion of the penis, as is common in Bradybaena similaris, is not observed. 2. The longest record of copulation was for 7.5 hours. 3. The first spawning takes place within 38-60 days after the last copulation. Eggs were laid underneath wet cotton one per ovulation with interval of 2-17 days. 4. Egg is ellipsoid in shape and milky white in colour with the size of 4.37×2.12 mm. During the experiment, a single globular egg was found. Egg membrane is jelly-like, soft and innumerable crystals of CaCO_3 are embedded therein. 5. A single shell ovulates 4 to 19 times a year. 6. In hatching, young preys on the egg membrane from inside. It hatches out 13-15 days after spawning. The hatched young also preys on the empty egg.

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