102 NILS HJ. ODHNER, STUDIES ON RECENT CHAMIDAE. 



Contents. 



Pag. 



Introduction 3 



1. The hinge structure of the adult Ckamidae 4 



2. The ontogenetical development of the hinge types in Chamidae 12 



3. The homologies of the hinge elements in Chamidae and the reasons for constituting the new genus 



Pseudochama 20 



4. Morphology of Pseudochama pusilla n. sp 24 



5. Anatomical researches on species of Pseudochama 32 



Echinochama arcinella Linné 32 



Pseudochama cxogyra Conrad 38 



Pseudochama ferruginea Reeve 39 



Pseudochama retroversa Lischke 42 



Pseudochama cristella Lamarck 45 



G. Anatomical researches on species of Chama 47 



Chama reflcxa Reeve 47 



Chama reflexa forma julcesi Reeve 49 



Chama sarda Reeve 52 



Chama gryphoides Linné 55 



Chama coralloides Reeve 57 



Chama lazarus Linné 59 



Chama pellucida Broderip 62 



7. Summary of and general remarks on the anatomy of Chamidae 63 



1. The gills 63 



2. The vascular system 69 



3. The digestive system 71 



4. The nervous system 73 



5. The nephridia 73 



8. Subtlivision of the recent Chamidae and taxonomical remarks on single species 74 



Taxonomical remarks on the genus Chama 76 



Taxonomical remarks on the genus Pseudochama 80 



Geographical distribution of the Chamidae 82 



Fossil forms of Chama and Pseudochama 83 



9. On the origin of the recent Chamidae 84 



List of works referred to 95 



Reference letters on the figures 98 



Explanation of figures 99 



Tryckt den 27 oktober 1919. 



Uppsala 1919. Almqvist & Wiksells Boktryckari-A.-B. 



