TABLE OF CONTENTS. 



PAGE 



Preface xi 



Introduction I 



Richness of the Starfish Fauna ; Causes I 



Food and Feeding Habits of the Starfishes 3 



Activities of Starfishes ; Migrations ; Rate of Travel 4 



Larval Stages ; Protection of Elggs and Young ; Incubation 7 



Senses ; Instincts ; Memory ; Acquired Habits 9 



Peculiarities of the Starfish Fauna of the Northwest Coast of America 11 



Multiplicity of Rays ; Variability 12 



Subspecies and Varieties 17 



Hybridism of Associated Species 18 



Faunal Relations and Distribution of the Species 18 



Morphological Features of the Qass Asterioidea 20 



Classification of the Asterioidea 24 



Order Forcipulosa or Forcipulata 24 



Various Kinds of Pedicellariae 25 



Families and Subfamilies of Forcipulosa 26 



Family Asteriidae 27 



I. Morphology and Growth of the Skeletal Ossicles (Text-fig. l). .. . 27 



II. Pedicellariae of the Asteriidje 30 



III. Relative Importance of Morphological Qiaracters in Asteriidi. .. . 31 



A. Modes of Growth and Increase in Number of Skeletal Plates 32 



B. Interactinal Plates and Spines 33 



C. Form and Arrangement of the Dorsal Ossicles 34 



D. Dorsal Spines ; Form and Arrangement 34 



E. Pedicellariae ; Special Forms (Text-fig. 2) 35 



F. The Madreporite or Madreporic Plate and surrounding Spines 36 



G. Jaws and Oral Spines (Text-fig. 3) 36 



H. Adambulacral Spines ; Arrangement 38 



I. Number of Rays ; Variability 38 



J. Arrangement of the Ambulacral Feet or Sucker-tubes (Podia) 39 

 K. Modes of Development; Brooding of the Young; Position of 



the Genital Pores 39 



Classification of Asteriidae 39 



Subfamily Heliasterinae 40 



Subfamily Pycnopodiinae 40 



Subfamily Stichasterinae 40 



Subfamily .\steriinae 42 



A. Generic Subdivisions of Asteriins 43 



B. Subdivisions of the .^steriina; having Definite Longitudinal 



Rows of Dorsal Plates and Spines 44 



C. Table of Extralimital Species of Coscinasterias and closely 



Allied Forms 46 



D. Observations on Various Genera 46 



(ix) 



