34 University of California Publications. [zoology. 



at an angle of 120°. Tertiaries arise similarly on secondaries 

 and may branch. All branches with 2-5 rings at the base, though 

 not always sharply marked. Hydranths usually on the distal 

 side of the branches; tentacles 24-27, in one whorl; prominent 

 nettle cells in a close spiral on each tentacle ; hypostome trumpet 

 shaped. 



Gonosome absent (December, 1901). 



Growing at the surface, on a float at the ferry landing. 



Eudendrium ramosum Linn. 



TubuUiria ramosa, Linn., Syst. Nat., ed. X. 



Eudendrium ramosum, Ehrenberg, Corallenth. des r. Meeres. Abh. Bed. 

 Ac, 1832, p. 296. Allman, Gvm. Hyd., 1871, p. 332. 



Distribution. Pacific Grove, Cal. Great Britain (Allman). 

 Adria, Rovigno, Jan Mayen (Mark. T.) 



The gonosome is not present, but the trophosome agrees in 

 all details, save size, with the description and figure in Allman's 

 monograph. Length of tallest stem 35 mm. 



Not previously reported from the Pacific Coast. 

 Fam. Hydractiniidae. 



Trophosome. Two sorts of persons : olavate or cylindrical naked hydranths 

 arising from the encrusting hydrorhiza, with a circlet of filiform tentacles 

 and a conical or clavate proboscis; spiral zooids, usually at the edge of the 

 colony. Hydrorhiza may be beset with spiny processes. 



Gonosome. Sporosacs borne upon more or less specialized hydranths. 



Hydractinia Van Ben. 



With the characters of the family. 



Hydractinia milleri, sp. nov. 



PI. II. Figs. 15, 16, 17, 18, 19, 20. 



Trophosome. Sterile hydranths with 8-20 filiform tentacles, which in 

 contraction may be seen to be arranged in closely approximated alternating 

 series of four each around the base of a clavate (in contraction subconical) 

 proboscis. Larger ones 3-5 mm. long (preserved specimens). Spiral zooids 

 at the edges of the colony about as long as the sterile hydranths, but much 

 more slender; end knobbed, the whole structure resembling a very long 

 tentacle. Processes from the encrusting hydrophyton, tubular without 

 spinules or coenosarcal investment, i-1 mm. in length. 



Gonosome. Fertile hydranths, usually not more than one half as long as 

 sterile ones and more slender, with 3-8 filiform tentacles around the base of 

 a long clavate proboscis, with a terminal mouth. Sporosacs borne on 

 hydranth about midway between base and tentacles. Male sporosacs 



