INTRODUCTION XIII 



Crinoidea 



Cystoidea 



Echinoidea 



Edrioasteroidea 



Eocrinoidea 



Haplozoa 



Holothurioidea 



Machaeridia 



Ophiocystoidea 



Ophiuroidea 



Paracrinoidea 



Somasteroidea 



GRAPTOZOA 

 PTEROBRANCHIA 



HEMICHORDATA 

 ENTEROPNEUSTA 



TUNICATA 



Copelata 



Ascideacea 



Thaliacea 

 CEPHALOCHORDATA 

 VERTEBRATA 



Pisces 



(Tetrapoda) 



Amphibia 



Reptilia 



Aves 



Mammalia 



Under each phylum are listed first the taxonomists who did not specify any 

 specialty within the phylum, and those whose specialties include the entire phylum. 

 These are grouped under side-headings that indicate either geographic restrictions, 

 ecological limitations, or paleontological distribution. Taxonomists are listed under 

 each heading in alphabetical order (all alphabetizing is by the first capital letter), 

 with parenthetical indication of further restriction of specialty, if this is known. 

 Three sets of abbreviations are used: (1) geological time periods, (2) zoogeograph- 

 ical regions, and (3) general ecological habitats. In this way restrictions of the 

 specialties can be shown by the side-headings and the parenthetical notes together. 

 The abbreviations are always in the following order: Under all headings small 

 letters come first and indicate the following: 



b, benthic p, parasitic 



bw, brackish-water s, soil-inhabiting 



fw, fresh-water t, terrestrial 

 m, marine 



Under all headings except "Fossils," the capital letters, alone or following the 

 small letters after a colon (:) show the zoogeographic realm or realms. These are: 



A, Australian Nt, Neotropical 



AG, Atlantic Ocean O, Oriental 



Ant, Antarctic Oc, Oceania 



Arc, Arctic P, Palearctic 



E, Ethiopian PO, Pacific Ocean 



H, Holarctic Trop, Tropics of World 



N, Nearctic W, World 



Under the headings "Fossils" the first capital or the first group separated by 

 commas shows the geological period or subdivision, as follows: 



C, Cenozoic Q, Quaternary 



M, Mesozoic R, Recent 



P, Paleozoic T, Tertiary 



