192 MEDUSA PROM BRITISH COLUMBIA AND ALASKA. [June 16, 



EXPLANATION OF THE PLATES. 



Plate XVII. 



Fig. 1. Codonium apiculum, sp. nov., p. 165. 

 2. Thaumantias cellularia, p. 172. 

 2 a. „ oral lobes expanded. 



21 „ oral lobe contracted. 



PlATE XVIII. 



Fig. 1. Tunis breviconis, sp. nov., p. 170. 



2. „ „ view of oral surface. 



Plate XIX. 



Fig. 1. Mesonema victoria, sp. nov., p. 180. 



1 a. „ ,, portion of bcll-margiu. 



2. ,, „ oral surface. 



3. FolyorcJiis minuta, sp. nov., p. 174. 



Plate XX. 



Fig. 1. Phialidium gregarium, p. 179. 



\a. „ „ crossingofradial canals on stomach-roof. 



2. Species incerta ?, p. 188. 



Plate XXL 



Fig. 1. Gonionemus agassizii, sp. nov., p. 185. 



2. „ „ aboral surface. 



3. „ „ section of bell. 



Plate XXII. 



Fig. 1. TolyorcMs mimda, sp. nov., p. 174. Transverse section of a 

 gonad showing the continuation of the cavitj' of the radial 

 canal into the gonad. 



2. Mesonema victoria, sp. nov., p. 180. Section of bell-margin. 



cir.c<zM.= circular canal of bell-margin. 

 ect.papil.—excTetion papilla. 

 'ue.=velum. 



3. Gonionemus agassizii, sp. nov., p. 185. Attachment pad. 



4. Codonium apiculum, sp. nov., p. 165. Section of bell-margin. 



cir.ca«.= circular canal. 



oc.=ocellus. 

 ten.ba. =base of tentacle. 



ve.=velum. 



5. Codonium apiculum, sp. nov. Section of stomach. 



