Notes on the Cupuladriidae (Polyzoa, Anasca)

Abstract

calcification at the centre does not seem to occur.The broken zooecia which were distal in position in a fragment regenerate zooecia distally, those which were proximal, regenerate zooecia proximally, in which the zooecial orientation is reversed.Zooecia growing from the lateral walls of old zooecia, are at right angles to the previous direction of growth of the fragment.Each broken zooecium produces one bud laterally from the mid-line of its basal wall, and another bud arises from beneath the vibracular chamber.These zooecia are wide and often slightly distorted (see p. 175).Subsequent budding of radial series, including intercalary rows, is exactly the same as in zoaria developing from an ancestrula.The usual radial alternation in the asymmetry of the vibracular opesia is established in the primary and secondary series of buds (see Text-fig. 3 A).The colony of C. elongata Sakakura mentioned as distorted by Marcus & Marcus (1962 : 288) is, in fact, such a regenerating fragment.Marcus & Marcus (1962 : 301) have described a second form of regenerative or " zoarial budding ", in which small, fan-shaped zoaria are produced from a single zooecium at the periphery of the parent colony.This form of budding has been seen so far only in the D. umbellata-complex (e.g.