[fkaserI HYDROIDS OF THE VANCOUVER ISLAND REGION 193 



distant, tubular but narrowed distally, scarcely immersed; margin 

 with four low teeth; operculum of four flaps; surface annulated. 



Gonosome. — Unknown. 



Distribution.— Albatross Station 2873, N. 48° 30', W. 124° 57', 

 40 fathoms (Nutting); Swiftsure Shoal. 



Sertularella tenella (Alder) 



PI. XXXI, Fig. 116 



Scrtularia tenella Alder, Cat. Zooph. Northumberland, 1857, p. 23. 

 Sertularella tenella Fraser, West Coast Hydroids, 1911, p. 71. 



Trophosome. — Colony small; branches usually absent, when pre- 

 sent like the main stem; stem slender, geniculate, divided into regular 

 internodes; hydrothecse alternate, one to each node, very distant, 

 scarcely immersed, fusiform, annulated with the neck smooth; margin 

 with four teeth ; operculum with four flaps. 



Gonosome. — "Gonangia ovate, slender, ringed transversely, 

 produced above into a short tubular orifice" (Hincks). 



Distribution.— Albatross Station 2865, N. 48° 12', W. 122° 49', 40 

 fathoms (Nutting) ; Puget Sound (Hartlaub) ; San Juan Archipelago 

 (Fraser); off Masett, China Hat, Alert Bay, Nanoose Bay, Departure 

 Bay, north of Gabriola I., off Protection I., Northumberland Channel, 

 Uodds Narrows, off Matia I., Friday Harbor, Swiftsure Shoal, Na- 

 whitti Bar. 



Description of gonosome and figure are taken from Hincks. 



Sertularella tricuspidata (Alder) 



PI. XXXI, Fig. II7 



Sertularia tricuspidata Alder, Ann. and Mag. N.H., 2nd. ser. 18, 1856, 



p. 356. 

 Sertularella dentifera Torrey, Hyd. of the Pacific Coast, 1902, p. 61. 

 Sertularella dentifera Fraser, West Coast Hydroids, 1911, p. 69. 

 Sertularella tricuspidata Fraser, Ibid., p. 71. 



Trophosome. — Stem slender, lax; branching irregularly, usually 

 alternate but sometimes dichotomous; stem and branches divided 

 into regular internodes, with one hydrotheca or a branch and a hy- 

 drotheca on each; hydrothecae alternate, distinct, very slightly im- 

 mersed, tubular, sometimes curved; margin with three distinct teeth; 

 operculum of three flaps; occasionally the hydrothecœ are very much 

 prolonged and the margin is reduplicated. 



Gonosome. — Gonangia numerous on stem and branches, oval, 

 with very strongly crested rugosities; a small tubular neck bears the 

 circular aperture. 



