[Book Reviews]

Abstract

DR. N. PETERS, who has done much work already on the peridinians or dinoflagellates, gives a good and detailed survey of the group. It is well known that they combine holophytic with holozoic nutrition and therefore are claimed by both botanist and zoologist. Some apparently feed exclusively as plants, others as animals, but many feed in both ways. The larger naked forms engulf others of their kind, as well as diatoms and other small prey. The presence of a large eye with well-developed lens in some of these and nematocysts in Polykrikos and others give a special interest to these unarmoured forms. Here we find chain formation both in the naked and armoured species, and the beginning of a multicellular state in which individuals are permanently fused and the nuclei are fewer in number than the cells themselves. There are many species known from the North Sea and Baltic, but not so many as there are in the Channel, possibly because the region has not been worked so much for these creatures. All species are well figured and they are easy to identify. We note the absence of Noctiluca, which is treated separately in another part of this publication.

Die Tierwelt der Nord- und Ostsee.

Begründet von G. Grimpe und E. Wagler. Herausgegeben von G. Grimpe. Lieferung 17. Teil 2.d₂: Peridinea, von Nicolaus Peters; Teil 3.d: Scyphozoa, von Thilo Krumbach. Pp. 13.84 + 88. (Leipzig: Akademische Verlagsgsesellschaft m.b.H., 1930.) 13.50 gold marks.