12 Journal of Entrjmologj- and Zoology 



CC. Hydrotheca in a single row on stem. 



D. Hydrocladia on erect stems. 



E. One or more intermediate internodes. Hydro- 

 theca as deep as long. 



PI u malaria setacea. 



EE. Septal ridges moderate, usually two in each in- 

 ternode. 



Plumularia lageniffra. 



DD. Hydrocladia modified as corbulae protecting gono- 

 theca. 



E. Median tooth straight. Nine teeth. 



Aglaophenia pluma 



EE. Eleven teeth, irregular. 



Aglaophenia !>trntlii(inide^ 



BB. Hydrotheca stalked, bell-shaped. 



C. Gonophores are sporosacs. 



CC. Gonophores are medusae. 



D. Pedicels in pairs. 



Ca ni pa n ula ria c.rig iin . 

 Obelia gracilis. 



DD. Pedicels not in pairs. 



E. Pedicels on shoulders produced from stem. 

 Obelia geniculata. 



EE. Pedicels not geniculated, branching on all 

 sides. 



Obelia commissurolis. 



Sertnlaria de.tmoide'^ Torrey and Eitdendriiini ramomni L. 

 obtained during the summer of 102' are not included in this key. 

 They were determined for us by Mr. W. S. Wallace of the Hopkins 

 Marine Station, Pacific Grove, Calif. 



TlBlLARIAE 



Corynidae: No basal whorl of tentacles, but with tentacles 

 scattered irregularly over the hydranth. Tentacles knobbed. Hy- 

 droid branched. 



Syncorync mirabilix (Ag. ) Torrey. U. C. pul). Zool. Vol. 1. 

 1902. p. 31. 



Hydranth cylindrical. Proboscis conical. Scattering, capitate 

 tentacles. Small. Bathymetrical range; exposed to breakers of 

 open sea or in quiet harbours, ours on exposed pier with 0. com- 



