REVISION OF RECENT BAIRDIIDAE 3 



tentative; it is hoped that further data ^\•ill confirm the trends sug- 

 gested here and permit greater detail and precision of distinction 

 '\\dthin this framework. 



Because of the Hmitation of time, especially time required for 

 illustration, this classification is based on relatively few "key" 

 characters taken in about equal number from the carapace and soft- 

 part anatomy. Empirical observation suggests that they jdeld rela- 

 tively consistent and distinctive differential diagnoses. However, as 

 methods for rapid and objective simultaneous evaluation of many 

 characters become more practicable, such as those of numerical 

 taxonomy, we may expect these subjective distinctions to be con- 

 firmed and ramified. Application of numerical taxonomic techniques 

 to Ostracoda has been hampered by lack of basic anatomical data. 

 One purpose of this study has been to accumulate anatomical and 

 homological information for the Bairdiidae, which stand in special 

 need of quantitative evaluation. Sufficient data are now available 

 for enough species to sustain an analysis of this type; it is only a 

 matter of selecting and codifying characters. 



This study, then, has a 3-fold purpose: (1) To identify and describe 

 some of the interesting and taxonomically significant species of modern 

 Bairdiidae collected by recent expeditions, especially in the Indian 

 Ocean region; (2) to evaluate and illustrate some of the variety of 

 carapace and appendage anatomy that is possible in this group; and 

 (3) to use this new^ information in establishing a tentative classifica- 

 tion, as a first step in the iterative process of achieving a generally 

 accepted and useful nomenclatural system for this family. Although 

 only living species are considered in this report, it is presumed that 

 the laxa established are equally appropriate for any post-Paleozoic 

 Bairdiidae. 



Acknowledgments 



This study forms a part of the project "Ostracodes of the Indian 

 Ocean," directed by Richard H. Benson, Division of Invertebrate 

 Paleontology, Smithsonian Institution, supported by grants to him 

 from the National Science Foundation and the Smithsonian Research 

 Foundation, and based chiefly on the collections of the United States 

 Program in Biology of the International Indian Ocean Expedition 

 (1963-1964). It was completed during my tenure as research associate 

 with Benson at the Smithsonian Institution (1965-1967), who also 

 put his collections and laboratory facilities at my disposal and con- 

 tributed the photographs assembled in Plates 1 and 2. 



Collections of other institutions and individuals have contributed 

 to this study. I should particularly like to thank Louis S. Kornicker, 

 Division of Crustacea, Smithsonian Institution, for the use of his 



