[fraser] HYDROIDS OF THE VANCOUVER ISLAND REGION 2W 



there may be different degrees in the same colony. I gave drawings of 

 gonangia of P. palmeri but I have since found that these vary as much 

 as the hydrothecse do. 



Plumularia setacea (Ellis) 



PI. XXXVI, Fig. 136 



Corallina setacea Ellis, Nat. Hist. Corallines, 1755, p. 19. 

 Plumularia setacea Fraser, West Coast Hydroids, 1911, p. 84. 



Trophosome. — Colony not large, sometimes reaching a height of 

 50 mm. but often much less; stem simple, divided into regular inter- 

 nodes, each bearing a hydrocladium, which is seldom branched; the 

 hydrocladia are regularly alternate and are in the same plane. After 

 the first internode which is short and without a hydrotheca, hydrothe- 

 cate and intermediate internodes alternate; the hydrotheca is placed 

 nearer the distal end of the internode; in many cases scarcely any 

 internodal septa can be seen but in other cases there may be an indica- 

 tion of as many as there are in P. lagenifera, in some parts of the colony ; 

 there are two supracalycine nematophores, one mesial nematophore 

 to each hydrocladial internode, with the exception of the proximal, 

 one on each cauline iuternode on the side opposite the hydrocladial 

 process and one in the axil of that process. 



Gonosome. — Gonangia borne on the hydrocladial processes of 

 the cauline internodes, much elongated, usually with a long neck and 

 circular aperture. 



Distribution. — Victoria (Torrey) ; Pt. Wilson (Calkins) ; San Juan 

 Archipelago (Fraser); Ucluelet, Northumberland Channel, Porlier 

 Pass, Fridav Harbor. 



