[fraser] HYDROIDS OF THE VANCOUVER ISLAND REGION 135 



Campanularia gelatinosa (Pallas) 



PI. XI, Fig. 29 

 Sertularia gelatinosa Pallas, Elench, Zooph., 1766, p. 116. 

 Laomedea pacifica A. Agassiz, III. Cat., 1865, p. 194. 

 Obelia gelatinosa Hincks, Br. Hydroid Zoophytes, 1868, p. 151. 

 Obelaria gelatinosa Hartlaub, Die Hydromedusen Helgolands, 1897, 



p. 488. 

 Obelia gelatinosa Calkins, Some Hydroids of Puget Sound, 1899, 



p. 357. 

 Campanularia pacifica Torrey, Hyd. from the Pacific Coast, 1902, 



p. 53. 

 Campanularia pacifica Fraser, West Coast Hydroids, 1911, p. 32. 

 Obelia gelatinosa Fraser, West Coast Hydroids, 1911, p. 39. 



Trophosome. — Stem fascicled, growing in clusters, reaching a 

 height of 200-250 mm.; larger branches are also fascicled; in the 

 fascicled portions the perisarc is thickened and dark in color, but in 

 the smaller branches and their ramifications it is whitish transparent. 

 As the small branches divide somewhat dichotomously, a large number 

 of hydranth pedicels appear close together and these in their whiteness 

 give the gelatinous appearance when in the water, to which evidently 

 the specific name is due. The branches have usually 3-5 annulations 

 at the base and the larger branches from which they spring have a 

 similar number above their points of origin. The hydranth pedicels 

 are slender, varying much in length; the shorter ones are annulated 

 throughout but the longer ones may have a smooth portion towards 

 the centre. The hydrothecse are deeply campanulate, tapering quite 

 gradually from margin to base; margin provided with about 10 teeth, 

 each provided with two cusps. 



Gonosome. — Gonangia elongated oval with distinct neck and taper- 

 ing base; pedicel short, annulated. 



Distribution. — Gulf of Georgia (A. Agassiz); Discovery Bay, 

 Wash. (Calkins); San Juan Archipelago (Fraser); Nanoose Bay, 

 near Clarke Rock, Northumberland Channel, Dodds Narrows, 

 Whaleboat Passage, off Matia I., Friday Harbor, off Brown I., Up- 

 right Channel, off O'Neale I., off Waldron I., San Juan Channel, Pt. 

 Townshend. 



Hincks in describing this species, says that it gives rise to free 

 medusae. As he usually was so very reliable, this statement has been 

 copied by many since his time, who have found only the trophosome. 

 Apparently the error was not noticed until Hartlaub, working on 

 Heligoland hydroids, found abundant material for the study of the 

 species. His investigation apparently established beyond doubt 



