Some remarks on the systematics of the Mitostoma chrysomelas-group (Arachnida, Opilionida, Nemastomatidae)

CONTENTS Ι. Introduction 2. The characters used in literature compared with those of the Westpolder material 1. Denticles of the dorsal surface 1. The number of transverse rows of continuous denticles 2. The row of denticles along the border of the scutum 3. Denticles in front of the ocularium 4. Interruptions of the transverse rows of denticles 5. The number of areas on the cephalothorax 6. Isolated denticles 2. Colour pattern 3. Limbs 4. Chelicerae 5. Copulatory organ 3. Identity of the Westpolder Mitostoma 4. Description of Mitostoma chrysomelas (Hermann, 1804) 5. Acknowledgements 6. Literature 1. INTRODUCTION Many authors (Roewer, 1923, 1951; Šilhavý, 1939; Rambla, 1956; and Spoek, 1963) have described one or more species and subspecies of the Mitostoma chrysomelas-group. While studying extensive material of apparently one species collected in one particular area practically all characters used in literature for distinguishing the species and subspecies of this group proved to be liable to considerable variation.