S. F. Clark — Sydroids of the Pacific Coast. 255 



thecffi and by their shajjc, not being rounded at the base ; by the form 

 of tlie gonotliectp, wliicli are sessile and liave a circular terminal 

 aperture. 



Found creeping on the old stems of a MtdendriuniWke form, 

 taken at Santa Cruz, Cal., Bay of Monterey, by Dr. C. W. Anderson. 



The variation in the lengtli of the stems is very great ; sometimes 

 they are aboiit equal to the length of the hydrothecjje, and again 

 they will be five or six times that length. The stolon is quite 

 uniformly twisted and is at least twice the diameter of the stems. 



Halecium tenellum. Hincks. 



Halecium tenellum Hincks, Annuls and Map;, of Nat. Hist., 3, VIII. 252, pi. VI. 



Plate XXXIX, figure 5. 

 Some very good specimens of this delicate species have been 

 received from San Diego. There were no gonothecfe but the hydro- 

 some is so exactly similar to our New England specimens and to the 

 figure and description of Hincks that I do not hesitate to call it the 

 same. A glance at our figure will show how exactly it corresponds. 

 Found parasitic on a species of Bimeria, collected on the piles of 

 wharves, San Diego, Cal., — Dr. E. Palmer, 18Y5. 



Sertularia anguina Trask. 



Sertularia anguina Trask, Proc. Cal. Acad. Nat. Sci., 112, Plate V, fig. 1. March 



30, 1857. 

 Sertularia Inhrata Murray, Ann. and Mag. for April, 1860, 250, Plate XI, fig. 2. 



Plate XL, figures 1, P, 2. 

 Stems clustered, simple, erect, straight from the proximal end to 

 the first branch, above the first branch flexuous, becoming more and 

 more so toward the distal end, sparingly branched, divided by trans- 

 verse joints into short internodes, those below the first branch bearing 

 a single pair of nearly opposite hydrothecre, while those above the 

 first branch have three hydrotheese and give origin to a single branch ; 

 branches regularly alternate, ascending, slightly curved, mostly short, 

 a few have a much larger growth and exactly imitate the main stems 

 in every particular; color corneous. Hydrotheca3 nearly opposite, 

 somewhat flask-shaped or tapering evenly to the distal end with- 

 out any constriction or flask-shaped neck ; aperture usually entire, 

 slightly oblique, facing toward the stem, or with the outer margin 

 much more produced than the inner and in some cases showing a dis- 



