Anatomical studies on the arthrodiran head Part 1 Preface, geological and geographical distribution, the organization of the Arthrodires, the anatomy of the head in the Dolichothoraci, Coccosteomorphi and Pachyosteomorphi. Taxonomic Appendix. - Stensio, Erik Andersson (Kungl. Svenska vetenskapsakademiens handlingar, 4 ser., 1963)