156 THE ROYAL SOCIETY OF CANADA 



Cocconeis scutellum. 



Coscinodiscus asteromphalus, 



C. excentricus, 



C. radiatus. 



Epithemia zebra, 



Fragillaria capucina (Staurosira capucina), 



Grammatophora marina, 



G. serpentina, 



Hyalodiscus laevis, 



H. subtilis, 



Licmophora Lyngbyei, 



Melosira nummuloides, 



M. Borreri, 



Navicula aspera (Trachyneis aspera), 



N. elliptica (?), 



N. humerosa ( ?), 



N. Lyra, (?), 



N. Smithii. 



Nitzschia sigma, 



Rhabdonema arcuatum, 



Rhizosolenia setigera, 



Surirella, 



Synedra. 



More Rare Species. The uncommon or rarely occurring species 

 are too numerous to be listed, and would only duplicate unneces- 

 sarily the general list appended. The following appear to be the 

 more interesting of this class: 



Asterionella, 



Amphitetras (Triceratium) , 



Arachnodiscus Ehrenbergii, 



Asteromphalus arachne, 



Asterolampra, 



Aulacodiscus Oregonus, 



Auliscus coelatus, 



A. sculptus. 



Campyloneis Grevillei, var. Argus, 



Cerataulus polymorphus, 



Campylodiscus Thuretii, 



Cocconeis interrupta, 



Dimmerogramma, 



Ditylum Brightwellii (Triceratium undulatum), 



Ethmodiscus punctigera, 



