148 THE ROYAL SOCIETY OF CANADA 



Gonothyraea clarki (Marktanner-Turneretscher) 



PI. XIV, Fig. 46 



Laomedea (Gonothyrœa) clarki Marktanner-Turneretscher, Hy- 



droiden von Ostspitzbergen, 1895, p. 408. 

 Gonothyrœa clarki Fraser, West Coast Hydroids, 1911, p. 37. 



Trophosome. — Colonies branched, "stem and branches slender, 

 internodes long; main stem annulated above each of the branches; 

 branches annulated at the base and above the origin of smaller 

 branches and pedicels; hydrotheca pedicels arranged alternately, 

 the branches slightly geniculate where they are given off, short and 

 usually annulated throughout; hydrothecse deeply campanulate 

 narrowing very slightly in the distal half and somewhat more in the 

 proximal; margin with 10-12 sharply truncated teeth, giving a 

 castellated appearance to the hydrothecse. 



Gonosome. — Gonangium oval or oblong, usually growing in the 

 axils of branches or pedicels but occasionally taking the place of 

 hydrothecse ; medusoids four or five in each gonangium. 



Distribution. — Bare Island (Hartlaub) ; Departure Bay, San 

 Juan Archipelago (Fraser); Departure Bay, Nanaimo, Dodds Nar- 

 rows, Gabriola Reefs, Friday Harbor. 



This species was quite common on the rocks in Departure Bay 

 and on the floats in Nanaimo Harbor. In April the gonosome was 

 present and it was possible to obtain various stages in the development 

 of the planulse. There was little evidence that fertilization takes 

 place within the capsule, although in one or two cases the ova showed 

 signs of division. In no case was there any sign of tentacles on the 

 medusoid until after its escape from the gonangium. The number 

 of ova in a sporosac varies from 1 to 4. The developing planulse 

 are not placed in any definite position in the sporosac but are found 

 lying in all directions. 



Gonothyraea gracilis (Sars) 



PI. XV, Fig. 47 

 Laomedea' gracilis Sars, Beretning om en Zool. Reise i Lofoten og 



Finmarken, 1851, p. 18. 

 Gonothyrœa gracilis Allman, Ann. and Mag. N.H., 3rd ser., 13, 1864, 



p. 374. 

 Gonothyrœa gracilis Hincks, British Hydroid Zoophytes, 1868, p. 183. 



Trophosome. — Colony irregularly branched; stem, branches and 

 pedicels long and slender; branches and pedicels bend abruptly 

 near the origin and pass upward in the same direction as the main 

 stem; stem with several annulations at the base and above the origin 



