Hydracarina from the Wellington Province

Abstract

Seven species of Hydracarina are described, all of them new, three belonging to the Genus Hydrachna, one to the Genus Eylais, one to the Genus Piona and two to the Genus Arrenurus, and their possible relationships discussed. The life history of a species belonging to each of the first three genera has been carefully followed, although this has so far been accomplished overseas with only one species. The gross anatomy of the female of the Eylais species is given and compared with an account by Croneberg in 1878 of the anatomy of Eylais extendens, information on this account having been obtained from a paper by Michael (1895). A comparison is also made with the normal acarid anatomy, pointing out the line of departure. Ecological notes are given, including some observations on the possible factors influencing the local distribution of hydrachnids.