58 University of California Publications. [zoology. 



Colonies in San Pedro Harbor liberated medusae in December, 

 1901. The medusae possessed from 20-24 tentacles, this varia- 

 tion correlated with a variation in the number of tentacles in the 

 several quadrants, and the spacing of the lithocysts. This is the 

 only departure from the type described by Hincks. 



All the colonies were growing on kelp when collected, save 

 those in San Pedro Harbor, where they were fastened to the 

 float at the ferry landing. In all cases they were near the 

 surface except at the Corouados Is., where they came up in a 

 haul at 18-24 fathoms. 



Obelia genieulata (Linn). 



Sertularia genieulata, Linnaeus, Syst. Nat. 



Encope diapkana, Agassiz, Contr. N. H. U. S., 1862, IV, p. 322. 



Obelia genieulata, Allman, Ann. Nat. Hist., 1864. 



Distribution. San Francisco, Cal., between tides; Catalina 

 I., Cal., in 42 fathoms. New Zealand (Hartlaub). Eastern 

 U. S. (Agassiz). Europe (Hincks). 



The length of internodes and the thickening of perisarc 

 below the shoulder processes vary widely in the same stem. 

 Near the bases of some stems there are no thickenings below the 

 shoulders at all; they appear only near the tips. 



The Catalina colonies were growing on a frond of Macrocystis; 

 the gonothecae were loaded with medusae (June 28, 1901). The 

 San Francisco colonies were found on boulders in the breakers 

 at the entrance of the Bay, also with medusae in the gonothecae 

 (Dec. 14, 1895). 



Clytia. 



Trophosome. Colony not regularly branched. Hydrothecae with long 

 pectteels. 



Gonosome. Gonophores liberated as medusae, with four tentacles. 



Clytia compressa (Clark). 



PI. VI. Fig. 49. 

 Campanularia compressa, Clark, Proc. Ac. N. So. Phil., 1876, XXVIII, 



p. 214. 

 Clytia compressa, Nutting, Proc. Wash. Ac. Sc, 1901, III, p. 170. 



Distribution. San Diego (5 fathoms) and San Pedro (3 

 fathoms), Cal. Orca, Al. (Nutting). Shumagiu Islands (Clark), 

 6-20 fathoms, on Laminaria. 



