Some Intertidal Sessile Barnacles of New Zealand. By Lucy B. Moore. [Read before the Wellington Branch, July 28, 1943; received by the Editor, August 30, 1943; issued separately, March, 1944.] This paper deals with the four most abundant and most conspicuous Balanomorph. barnacles occurring intertidally in the main islands of New Zealand. The accompanying key summarizes the features by which they may be distinguished from other intertidal barnacles and from one another. Other cirripede species that have been recorded for the littoral of New Zealand are listed at the end of the account. Among them Tetraclita purpurascens and Balanus spp., especially B. trigonus, occur on shells and under stones at about low tide mark in many places, but they have not been seen by the present writer to form conspicuous bands. Stalked barnacles are quite abundant in well-shaded, damp crevices, or under overhanging rocks at about high tide level, usually on a fairly open coast. Key. 1. Parietal valves of adult 6, basis calcareous Balanus. Parietal valves of adult not 6, basis membranous 2. 2. Parietal valves of adult firmly and completely fused into a ring 4.Chamœsipho Parital valves of adult 4: rostrum with radii 3. 3. Parietal valves porose Tetraclita. Parietal valves not porose 5. Elminius. 4. Rarely exceeding 5 mm. diameter: body navy blue C. columna. Fully grown shell about mm. diameter: body brownish C. brunnea. 5. Parietal valves closely plicate internally at base: average diameter c. 15 mm. E. plicatus. Parietal valves smooth internally at base: average diameter c. 5 mm. E. modestus. Previous work on the recent barnacles of New Zealand has been predominantly systematic, in the form of reports on specimens collected by various expeditions. An intensive study of local forms begun by L. S. Jennings was cut short in 1914 by war service from which he did not return. Some of his results were published (1918). Linzey (1942a) has listed the Balanomorph barnacles collected by Oliver on the Kermadec Islands, and (1942b) has described the body appendages of Balanus decorus. Ecological data are provided by Oliver (1923). In classifying the biotic communities of the littoral belt of New Zealand, he includes in his “shelled-animals formation” a sessile cirripede subformation within which he differentiates an Elminius plicatus association, an Elminius modestus association, and a Chamæsipho association. These he exemplifies by descriptions of specific localities, listing the plants and animals that accompany the dominant barnacle in each case. Cranwell and Moore (1938), in a discussion of the intertidal communities of the Poor Knights Islands, off the North Auckland east coast, define two associations with sessile barnacles as dominants,