Further notes on the Holothyrina (Acarida) : I. Supplementary description of Holothyrus coccinella Gervais

The present paper is the first part of a series of two studies dealing with the morphology of the suborder Holothyrina. Some years ago (Van der Hammen, 1961), I published already an extensive description of a species from New Guinea (Holothyrus grandjeani Van der Hammen), in which paper I pointed to a number of important characters generally neglected in the study of Anactinotrichida. Because my material of H. grandjeani contained only one adult specimen, a number of characters (e.g. details to be studied in transverse as well as in longitudinal sections) could, however, not be taken into consideration. As a result of my 1961 study, a reinvestigation of nearly all species of Holothyrus, and especially of the type-species (H. coccinella), became highly desirable. In a paper on the morphology of Glyptholaspis confusa (Foà), a Gamasine mite (Van der Hammen, 1964), I continued my studies in Anactinotrichid morphology. Several views which I developed there necessitated a return to Holothyrus. A new investigation could be carried out by the discovery of additional material in our museum collection, and by the acquisition of further specimens. Because I have now two females of H. coccinella from Mauritius at my disposal, the first paper of the present series deals with the type-species of the genus. In a second part (to be published afterwards), material from New Guinea will be used to clear up some of the remaining problems. The study of H. coccinella has been carried out in the same way as that of Glyptholaspis confusa (cf. Van der Hammen, 1964); this applies not only to the description, but also to the ways of observation, the preparation of sections, and the orientation of figured structures. Some of the figures