TABLE OF CONTENTS. 



Introduction 3 



Paleontological evidence as to the position of Chimseroids 3 



Anatomical evidence as to their position 4-9 



Taxonomy of living forms 6-7 



Collecting notes 7-10 



Habits of Chimsera colliei; color, size, distribution, movements.. . 11-18 



Sexual differences, food " 19-21 



Breeding 23-25 



Mode of depositing eggs 25-27 



Rate of embryonic development 27 



Egg and its capsule 27-40 



General plan of development 41 



Primary egg membranes 42-45 



Yolk 45-46 



Germinal vesicle 47 



Fertilization 48-52 



Segmentation 52-63 



Gastrulation 63-92 



Early embryos 75-ioi 



Late embryos 102-109 



Comparison with other Chimceroids 109-1 1 1 



"Larval" Chimsera 111-114 



Organogeny 1 14-132 



Relationships of fossil Chimseroids 133-155 



Summary of evidence bearing upon the position of Chimseroids . . .155-156 



Bibliography 159-172 



Description of plates 174-194 



ERRATA. 



Page II, for Regne read Regne. 



Page 30, second column, after Rhinochim^ra pacifica, for 3 read 33. 



Page 36, fig. 20, for Rhinochimsera read Harriotta (?). 



