The Classification of Protozoa 115 



of the better known species are described recognizably in general taxa- 

 nomic works that are widely accessible. In addition, there are increasing 

 numbers of monographs dealing with single genera or families. It is only 

 in the areas not adequately covered by general monographs and not yet 

 touched by special surveys, that the protozoologist encounters major diffi- 

 culties. In such cases, identification of a species may involve a laborious 

 search through isolated and sometimes numerous papers dealing with 

 members of the genus in question. 



For those who are beginning to cultivate an acquaintance with the 

 Protozoa, an illustrated key written by Jahn and Jahn (13) will prove 

 to be very helpful. The authors have explained the use of taxonomic keys 

 and have included instructive discussions of the criteria to be considered 

 in identifying members of the major groups. This key also will be useful 

 to the advanced student who has not specialized in taxonomy of the 

 Protozoa. For species not listed by Jahn and Jahn, more extensive taxo- 

 nomic works must be consulted. A number of these special monographs 

 are listed in Chapters IV-VII. 



LITERATURE CITED 



1. Andresen, N. and H. Holter 1949. Science 110: 114. 



2. Biitschli, O. 1880-1889. "Protozoa" in Bronn's Klassen und Ordnungen des Thier- 



reiclis (Leipzig). 



3. Calkins, G. N. 1901. The Protozoa (New York: Columbia Press). 



4. 1926. The Biology of the Protozoa (Philadelphia: Lea & Febiger). 



5. 1933. The Biology of the Protozoa, 2d ed. (Philadelphia: Lea & Febiger). 



6. Caiman, W. T. 1949. The Classification of Animals: an Introduction to Zoological 



Taxonomy (New York: J. Wiley & Sons). 



7. Doflein, F. 1902. Arch. f. Protistenk. 2: 169. 



8. and E. Reichenow 1927-1929. Lehrbuch der Protozoenkunde (Jena: G. 



Fischer). 



9. Dujardin, F. 1841. Histoire naturelle des zoophytes (Paris). 



10. Ehrenberg, C. G. 1838. Die Infusionsthierchen als volkommene Organismen 



(Leipzig). 



11. Goldfuss, G. A. 1820. Handbuch der Zoologie (Niirnberg). 



12. Hartmann. M. 1907. Arch. f. Protistenk. 10: 139. 



13. Jahn, T. L. and F. F. Jahn 1949. How to Knoiv the Protozoa (Dubuque: W. C. 



Brown Co.). 



14. Kent, W. S. 1880-1882. A Manual of the Infusoria; including a description of all 



known flagellate, ciliate and tentaculiferous Protozoa, British and foreign, and 

 an account of the organization and affinities of the sponges (London). 



15. Kudo, R. R. 1931. Handbook of Protozoology (Springfield: Thomas). 



16. Minchin, E. A. 1912. An Introduction to the Study of the Protozoa (London: 



Arnold). 



17. Miiller, O. F. 1786. Animalcula infusoria fiuviatilia et marina (Havniae et Leipzig). 



18. Pearse, A. S. 1936. Zoological Names. A List of Phyla, Classes and Orders (Durham: 



Duke University Press). 



19. Pringsheim, E. G. 1949. Pure Cultures of Algae. Their Preparation and Maintenance 



(Cambridge). 



20. Siebold, C. T. E. and H. Stannius v. 1845. Lehrbuch der vergleichende Anatomic, 



H. 1. 



21. Stein, S. N. F. v. 1859-1883. Der Organismus der Infusionsthiere (Leipzig). 



22. Swezy, O. 1916. Univ. Calif. Publ. Zool. 16: 185. 



23. Wenyon, C. M, 1926. Protozoology (London: Balli^re, Tindall & Cox), 



