NO. 5 fraser: hydroids 251 



Utria; Bindloe Island, Galapagos, 15 fathoms; NW of North Seymour 

 Island ; west coast of South Seymour Island ; west coast of James Island ; 

 Conway Bay, Indefatigable Island; Osborne Island in Gardner Bay, 

 Hood Island. 



Thuiaria fabricii (Levinsen) 

 Sertularia fabricii Levinsen, Vid. Middel. Natyrh. Foren., 1893, p. 190. 

 Thuiaria fabricii Fraser, Hyd. Pacific Coast, 1937, p. 168. 



Distribution. — West of Fossil Point, Coos Bay, Ore., 4-6 fathoms. 



Thuiaria insociabilis, new species 

 Plate 29, Fig. 22 



TrophosoTTie. — The colony observed was small, 13 mm; the main 

 stem is neither straight nor rigid. There are 2 branches, 6 mm and 5 mm, 

 both on the same side of the stem ; there is a hydrotheca in the axil of each 

 and 1 hydrotheca on the side of the stem between the 2 branches. The 

 branches are more slender than the stem but otherwise resemble it. A 

 process from the stem supports each branch and there is a distinct joint 

 at its terminus; the proximal part of the stem is quite slender. The hydro- 

 thecae are alternately arranged, the distance between 2 in succession being 

 about twice the length of the hydrotheca. The hydrotheca is nearly tubu- 

 lar, but tapers slightly towards the margin, curving slightly but regularly 

 from base to margin, almost wholly immersed. There are no noticeable 

 teeth on the margin ; the operculum consists of a single, abcauline flap. 



Gonosome. — Not observed. 



Distribution. — Station 1273-41, 5 miles NE of Anacapa Island 

 Lighthouse, 125-135 fathoms. 



Thuiaria similis (Clark) 

 Sertularia similis Clark, Alaskan Hyd., 1876, p. 219. 

 Thuiaria similis Fraser, Hyd. Pacific Coast, 1937, p. 171. 

 Distribution. — Puget Sound. 



Thuiaria simplex Fraser 

 Thuiaria simplex Fraser, Hancock Hyd., 1, 1938, p. 55. 

 Fraser, ibid., 3, 1938, p. 135. 



Distribution. — Off Cape San Francisco, Ecuador, 15 fathoms; Santa 

 Elena Bay, 8-10 fathoms. 



