REPORT ON THE CRINOIDEA. 



IX 



Family Hyocriiiidic, and Defiuition of Hyocrinus, 



A. General Account of the Type, Hyocrinus lethellianm, Wyville Thomson, 



B. On the Systematic Position of Hyocrinus, . 

 Family Bourgueticrinidse, .... 



Definition of genus Bathycrinus, . 



Structure of the Calyx, 



Distribution of the Axial Cords, 



Trifascial Articulations of the Outer Radials and Arm-Joints, 



The Disk, .... 



Axial Cords of tlie Arms, 



Comparison of Bathycrinus and Rhizocrinus, 



Bathycrinus campbellianus, n. sp., 



aldrichiaiius, Wyville Thomson, 

 gracilis, WyvOle Thomson, 

 Definition of Genus RMzucrinus, 



Characters of Conocrinus, 



Composition of the Calyx in Rhizocrlnus, 



Views of Pourtales, Sars, and Ludwig, 



Distribution of the Axial Cords, 



Syzygies in the Arms, 



Affinities of Rhixocrinus, 



Rhizocrinus lofotensis, ]\I. Sars, 

 rawsoni, Pourtales, 



Variations in the Shape of the Calyx, . 



The genus Deniocrinus, Perrier, 

 Definition of the family Pentacrinidse, 



Synopsis of the Genera, 



Genus Pentacrimis, 



A. Characters of the Geuus, 



Characters of Extracrinus, 

 Cenocrinus and Neocrimis, 

 Cainocrinus, .... 

 Variations in the Size of the Basals in Pentacr 

 Arms of Pentacrimis, . 

 Characters of the Stem, 



B. On the Characters of Young Pentacrinidre, 



C. The Calyx and its Contents, 



D. The Geological History of Pentacrimis, 

 Synopsis of the recent Species, . 



Pentacrinus asterius, Linn. sp. 



miilleri. Oersted, . 



maclearanns, Wyville Thomson, 



wyville-thomsoni, Jeffreys, . 

 Termination of the Stem below, and the Mode of 

 Pentacrinus alternicirrus, n. sp., 



naresianus, n. sp., 



Makei, P. H. Carpenter, . 



decorus, Wyville Thomson, 

 Variability of its Character.*, . 

 Pentacrinus mollis, n. sp., 



(ZOOL. CHALL. EXP. PART XXXII. 1884.) 



Attachment of the Pentacrinidie, 



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