66 University of California Publications. [zoology. 



proximal portion of each internode is a pair of hydrothecae opposite and 

 contiguous for half their length on one side of the stem. Each hydrotheea 

 is well immersed, bending outward rather sharply in its distal half and 

 narrowing slightly to a more or less bilabiate operculate aperture. 



Gonosome. Gonotheeae borne on stem; sessile, ovate, with a wavy out- 

 line and broad round aperture; half as broad as long. Single gonophore 

 centrally placed, with coenosarcal processes connecting it on all sides with 

 gonothecal wall. 



Distribution. San Diego, (1-25 fathoms), San Clemente I., 

 (42 fathoms), San Pedro, Cal., (13 fathoms); rocky and sandy 

 bottom; growing usually on seaweed. 



The portion of each internode distal to the hydrothecae is 

 subject to considerable variation in Length, so that the stems may 

 have a rather stringy or a robust habit. The aperture of the 

 hydrotheea is never conspicnonsly bilabiate; the greater diameter 

 is transverse. 



Sertularia furcata Trask. 



PI. VIII. Figs. 73, 74, 75. 



Sertularia furcata, Trask, Proc. Cal. Ac, 1854, I, p. 112. Clark, Tran; . 

 Conn. Ac, 1876, III, p. 258. 



Distribution. Near San Pedro, Cal., 9 fathoms; Coronados 

 Is., 18-24 fathoms; San Diego, 5 fathoms; San Francisco, shore 

 rocks. Farallone Is., Cal., (Trask). Santa Barbara and Santa 

 Cruz, Cal., (Clark). 



Gonotheeae, hitherto unknown, were present in San Fran- 

 cisco (Nov. 24, 1897) and San Diego (July, 1901) colonies. 

 Gonotheca broadly ovate, compressed, with moderate terminal 

 aperture; blastostyle connected with gonothecal wall by numerous 

 branching coenosarcal processes; two elongate ovate gonophores. 



The San Francisco colonies were growing on erect stalks of 

 Phyllospadix. The steins are short and project from all sides of 

 the eel grass. Each stem leaves the eel grass at an angle of 

 about thirty degrees, then bends quickly away so that for the 

 most part it makes an angle of seventy degrees with the stalk. 

 The hydrothecae of the first, and often of the second pair as well, 

 are not in contact. Those of succeeding distal pairs are not only 

 in contact for half their length but tend much more strongly 

 toward the upper side of the stem than do the proximal hydro- 

 thecae. This would seem to be an instance of the effect of gravity 



