564 SCIENTIFIC RECORD FOR 1834. 



a nef/ variety of Amygdalocystites Jiorealis as var. Icevis. The illustra- 

 tions are good. He records the existence in the Trenton limestone at 

 Brigham's Lake, Hull, of locrinus subcrassus, Glyptocrinus decadactylus, 

 and Gl. parvus. 



Chapman, E. J. — A Classification of Crinoids. (Trans. Eoyal Soc. Can- 

 ada, vol. I, section iv, 1882, pp. 113-116. Montreal, 1883.) [Ap- 

 peared 1884.] 



This classification is based on the presence or absence of a canalicu- 

 lated structure in the calyx and arm-plates. The author makes three 

 divisions with a subdivision in the first and second divisions. In the 

 first division the plates (apart from the stem segments) are without in- 

 ternal canals ; in the second the arm-plates are perforated internally ; 

 and in the third a system of canals radiates from the base of the calyx 

 to the extremities of the arms. The following is a summary of the clas- 

 sification : 



I. Emedullata : 



1. Amplicincta : 



1. Proclinata (e. g. Cheirocrinus). 



2. Attenuata {e. g. Pisocrinus; Hybocrinus). 



3. Spatiosa (e. g. Platycrinus). 



4. Piunigera {e. g. Poteriocrinus). 



5. Disjuncta {e. g. Marsupites). 



2. Multicincta: 



1. Squamosa (e. g. Ichthyocrinus). 



2. Copulata (e. g. Melocrinus ; Eucalyptocrinus). 



3. Ornata {e. g. Actinocrinus ; Glyptocrinus). 



4. Opulenta {e. g. Polypeltes). 



5. Mutica {e. g. Uintacrinus). 



II. Fistulata: 



1. Eamosa {e. g. Cyathocrinus) 



2. Foliata [e. g. Crotalocrinus). 



3. Fimbriata (e. g. Cupressocrinus). 



4. Quadrata (e. g. Gasterocoma). 



III. Canaliculata : 



1. Orassicincta : 



1. Frondosa {e. g. Pentacrinus). 



2. Vagata (e. g. Antedon). 



3. Florifera {e. g. Encrinus). 



4. Coadunata (e. g. Eugeniacrinus). 



5. Conformata {e. g. Apiocrinus; Bourgetticrinus ; Khi^o- 



crinus). 



2. Tenuicincta: 



1. Carinata (e. g. Hyocrinus). 



2. Truncata (e. g. Holopus). 



