TABLE OF CONTENTS. V 



Structure and anatomy Continued. 

 Radials Continued. 



Articular faces of the radials Continued. 

 Family Antedonidse Continued. 



Subfamily Bathymetrinre Continued. Page. 



Trichotuetra cubensis 65 



Nanornetra bowersl 65 



Thaumatometra tennis 66 



Family Pentametrocrinidse 68 



Pentametrocrinus japonicus 68 



Pentametrocrinus semperi 69 



Key to recent comatulids based upon character found in articular faces of radials 60 



Post-radial elements 78 



General features 78 



Post-radial homologies 103 



First brachial pair 103 



Homologies of the division series of two ossicles 104 



Eudiocrinus and Uintacrinus 105 



Pentametrocrinida; and Atopocrinus 107 



Homologies of the division series of four ossicles 108 



Irregularities in the occurrence of the division series of 4(3+4) 10S 



Systematic distribution of the division series of 4(3+4) 110 



Cfipillaster and Nemaster 110 



Comatella, Neocomatella, and Palrcocomatella 114 



Distal arm division 314 



Nomenclature of the different types of post-radial structure 116 



Adolescent autotomy and the reduplication of the arms 116 



Young of the comatulids 116 



Interpolated division series 118 



Process of arm reduplication 110 



Phylogenetic sequence of the arms on each ray 123 



Ontogenetical, phylogenetical. and morphological sequence of the first brachial 



pairs and their reduplications 325 



Braehials of the free undivided arm beyond the first pair 1-6 



Brachials of the arms of the multibrachiate species 129 



Arm tips 131 



Pinnules 132 



General features 132 



Oral or proximal pinnules 140 



Middle or genital pinnules 149 



Distal pinnules 154 



Pinnules and cirri 158 



Types of intersegmental union 150 



General features 150 



Union of radials with each other and with ceutrodorsal, and union of calyx plates_ 160 



Nonmuscular unions 162 



General remarks 1R2 



165 



Pseudosyzygy 174 



Synarthry 176 



Cryptosynarthry 177 



