TABLE OF CONTENTS. 



Page. 



1. Introduction — Acknowledgments, material, methods 1 



2. The structure and the life history of Protoopalina intestinalis 6 



3. A description of the known species and of the genera in the family 



Opalinidae 25 



4. The nuclear conditions in the Opalinidae 248 



5. Relationships among the Opalinidae and the criteria of species 259 



6. The relationships of the Opalinidae 265 



7. The hosts and the geographical distribution of the several species and 



groups of the Opalinidae, with a discussion of the distribution of 



the families and subfamilies of the Anura 271 



8. The Opalinid parasites and the geographical localities of the several 



species of liosts known to be infected by Opalinids 389 



9. A chronological review of the literature of the Opalinidae, supple- 



mentary to the chronological review published in the year 1909 as 



a part of the author's paper " Opalina " 431 



10. A list of the institutions in which are deposited sets of specimens of 



the species of Opalinidae 448 



11. A list of the literature to which reference is made in this paper 450 



12. Appendix I. Review of two additional papers upon Opalinids, supple- 



mentary to section 8 457 



13. Appendix II. The regional occurrence of the species of Opalinidae__ 461 



14. Index 471 



vn 



