[fraserI HYDROIDS OF THE VANCOUVER ISLAND REGION 125 



Trophosome. — Nutritive zooids at many different stages of growth 

 may be found in the same colony. They grow from a basal cœnosarc 

 that is well supplied with jagged spines; these may be conical like 

 those of H. echinata, they may be much blunter, more in the nature 

 of columns, or these may be joined to form a ridge of some length. 

 The zooids in a contracted state may be entirely below the tips of these 

 spines. The number of tentacles increases during development 

 until the number in the adult reaches 20-24. 



Gonosome. — Sporosacs begin to develop on the generative zooids 

 when they are very small, at which time they, i.e. the zooids, have a 

 greater number of tentacles, 10-12, than when the sporosacs are 

 fully developed, as then 3 or 4 seems to be the usual number. The 

 generative as well as the nutritive zooids are provided with mouths. 

 The sporosacs appear some distance below the tentacles, about 

 one-fourth the distance from the tentacles to the base of the zooid. 

 The ova are large and numerous. The male sporosacs are oval, 

 not nearly so large as the female. 



Color. — Pink, female gonophores orange. 



Distribution. — Departure Bay, San Juan Archipelago (Fraser) ; 

 common on gastropod shells all along the Strait of Georgia near 

 Departure Bay as indicated by the fact that it has been dredged north 

 of Nanoose Bay, in Nanoose Bay, at the entrance of Hammond Bay, 

 off Clarke Rock, off West Rocks, in various parts of Departure Bay 

 and at its entrance, east of Protection I., Northumberland Channel, 

 Dodds Narrows, Pylades Channel, Gabriola Pass; found also at Friday 

 Harbor. 



In the colonies of this species the nutritive zooids are arranged 

 around the outside, especially around the lip of the shell on which they 

 rest, while the generative zooids are aggregated towards the centre 

 in a dense mass. They are so close together and the mature sporosacs 

 are so large that it is almost impossible to see down to the basal 

 cœnosarc at any place. When the generative zooids are young they 

 fit down between the large spines and ridges so well that they are very 

 well protected. I have not seen any special sensory or protective 

 zooids present in any of the colonies. 



Hydractinia milleri Torrey 



PI. VII, Fig. 19 



Hydractinia milleri Torrey, Hyd. of the Pacific Coast, 1902, p. 34. 

 Hydractinia milleri Fraser, West Coast Hydroids, 1911, p. 27. 



Trophosome. — Colony growing from a basal cœnosarc, which is 

 provided with long smooth spines ; nutritive zooids robust when mature 



