vol. i.i Torn ij . — Hydroida of the Pacific Coo si . 79 



There are but two small fragments in tin lleetion. The 



coenosarc is Lacking in many places, but the perisarc is in good 

 condition, The internodes of the stem are of constant length, 

 separated by well marked nodes and each bearing distally one 

 hydrocladium. Each hydrocladial internode possesses mesial and 

 supraealycine nematophores, all monothalamic, as in P. goodei* 



The internodes of 1 »oth stem and hydrocladia arc much longer 

 than those of the latter species, and the hydrocladia are not so 

 strongly arched. The hydrothecae arc similar in shape. In the 

 hydrothecae of P. plumularoides arc scries of bosses similar to 

 those found in Halecium. 



Three empty gonothecae arc present, borne singly on the 

 cauline processes supporting the hydrocladia. All are evidently 

 immature, having no external aperture. They arc widesl dis- 

 tally, tapering abruptly from the truncated end to the base. The 

 wall is more or less irregularly wrinkled. 



Plumularia setacea (Ellis). 



PI. XI. Fig. 105. 



Sertularia setacea, Ellis, Nat. Hist. Zooph., 1786, p. 47. 



Plumularia setacea, Lamarck, Anirn. sans Vert., 1st ed., 1815, p. 129. 

 Calkins, Proe. Bost. Soe. N. H., XXVIII, 1899, p. 3G2. Nutting, 

 Am. Hydr. Pt. I. The Plumularidae, 1900, p. 56. 



Plumularia palmeri, Nutting, ibid, p. 65. 



Distribution. San Diego (1-25 fathoms), Avalon, San Pedro, 

 and San Francisco, Cal. Victoria, B.C. and San Diego (Nutting) . 



In a careful examination of numerous colonies of P. palmeri 

 from Monterey, San Pedro and San Diego, I was unable to find 

 any constant characters distinguishing it from P. setacea. The 

 colonies range in height from 5 mm. to 100mm. The longest 

 have the stoutest, darkest stems, and the most conspicuous 

 septal ridges. In the smallest colony the various ridges are 

 present or absent, usually weak when present, and the stem is 

 colorless, slightly sinuous toward the tip. The larger stems are 



*In both species the nematophores are delicate, with narrow bases, and 

 are frequently wanting, while their sarcostyles may remain. I have not seen 

 more than one supraealycine nematophore or sarcostyle to each hydrotheca. 

 Clark, who described /'. plumularoides, saw nothing of either. 



