130 THE ROYAL SOCIETY OF CANADA 



•just below hydranth. Hydranth with a proximal whorl and two 

 distinct but closely approximated distal whorls of filiform tentacles" 

 (Nutting). 



Gonosome. — "Gonophores attached directly to the hydranth 

 body without the intervention of peduncles and developing into 

 free medusae, each of which has a single large tentacle bearing succeed- 

 ing generations of medusae. The medusae are deeply campanulate 

 with four radial canals and short proboscis" (Nutting). 



Hybocodon prolifer Agassiz 



PI. X, Fig. 24 



Hybocodon prolifer Agassiz, Cont. Nat. Hist. U.S., IV, 1862, p. 243. 

 Hybocodon prolifer Nutting, Hydroids of Woods Hole, 1901, p. 341. 



Trophosome. — "Hydrocaulus unbranched, longitudinally striped 

 owing to the ccenosarcal canals showing through; perisarc suddenly 

 enlarging near the hydranth, where a number of collar-like swollen 

 rings appear, the uppermost being the largest. Hydranth much like 

 that of Tubularia but with two distinctly separated whorls of tentacles 

 around the proboscis, each whorl being composed of about 16 ten- 

 tacles, the lower being twice as long as the upper" (Nutting). 



Gonosome. — "Gonophores adnate to the hydranth body just 

 above the basal whorl of tentacles, producing free medusae with four 

 radial canals and 5 superficial meridional orange-colored bands when 

 fully mature. The single tentacle is greatly enlarged and near its 

 base a number of medusae in various stages of development are attached 

 and these again in the same manner may bear other groups of medusae" 

 (Nutting). 



Color. — "The pigmentation of both hydranth and medusa 

 is orange red" (Nutting). 



Distribution. — Medusa found at the Station float, Departure 

 Bay, Feb. 17, 1913. 



No Hybocodon hydroid has been found on this coast but since 

 the medusa has been, it seems well to include it here. I can detect 

 no difference between this medusa and Hybocodon prolifer and since 

 this one was found, Bigelow's paper has appeared in which he reports 

 50 excellent specimens from Dutch Harbor. 13 Some descriptions of 

 that species state that only one tentacle is present but Mayer refers 

 to the fact that as many as 3 may be present, 14 while Bigelow says 

 "Most of the specimens have three large tentacles, with one or two 

 medusa buds; but some have only one tentacle, some two and several 



13 Pacific Medusae and Siphonophorse, Proc. U. S. Nat. Mus., 1913, p. 6. 



14 Medusae of the World, vol. I, 1910, p. 39. 



