[fraser] HYDROIDS OF THE VANCOUVER ISLAM) REGION 197 



Thuiaria dalli Nutting 



PI. XXXII, Fig. 122 



Sertularia cupressoides Clark, Alaskan Hydroids, 1876, p. 220. 

 Thuiaria dalli Nutting, American Hydroids, pt. 2, 1904, p, 68. 

 Thuiaria dalli Fraser, West Coast Hydroids, 1911, p. 75. 



Trophosome. — Stem rather stout, branching regularly; branches 

 alternately arranged, characterized by the fact that they are twisted 

 at the base to be in a plane at right angles to the stem; each is sup- 

 ported on a projection from the stem, consisting usually of two or 

 more joints; hydrothecae nearly opposite, closely placed, almost 

 wholly immersed, margin with two teeth; operculum with two flaps. 



Gonosome. — (not previously described) Gonangia of the regular 

 Thuiaria type, not very large, obovate, with an aperture of good size, 

 and two shoulder spines more or less pronounced; each gonangium 

 is inserted without a distinct pedicel just below the hydrotheca. 



Distribution. — San Juan Archipelago, Dodds Narrows, Departure 

 Bay, Ucluelet (Fraser) ; Rose Spit, Naden Harbor, Cape Edenshaw, 

 Nawhitti Bar, Claninnick, Nanoose Bay, north of Gabriola I., 

 Northumberland Channel, Pylades Channel, Gabriola Pass, Porlier 

 Pass, Friday Harbor, Deer Harbor, Copalis. 



Although this species has been obtained in many localities at 

 a most all seasons of the year, for a long time no trace of a gonangium 

 appeared. Finally on June 6, 1913, while collecting at low tide on 

 Black Rock at the southwestern entrance of Porlier Pass many fine 

 specimens were obtained and among them several that had empty 

 gonangia, which supplied material for drawing and description. 

 None have been found with the sexual products present. 



Thuiaria distans new species 

 PI. XXXII, Fig. 123 



Trophosome. — -Stem erect, geniculate; branching regularly al- 

 ternate; branches long, slender, geniculate, either unbranched or 

 dichotomously branched; usually three hydrotheca? on the stem 

 between two successive branches on the same side; on the branches 

 the hydrothecae are alternate, very distant for this genus, each hydro- 

 theca placed at a bend in the branch; when the branch is dichotom- 

 ously branched there is a hydrotheca in the angle; hydrothecae largest 

 in the centre, tapering both ways, curved to turn well outward, with 

 the margin vertical, about one-half free; margin without distinct 

 teeth but rather bilabial; operculum of one abcauline flap. 



Gonosome. — Unknown. 



Distribution. — North of Gabriola I. 



