[fraser] HYDROIDS OF THE VANCOUVER ISLAND REGION 199 



Thuiaria similis (Clark) 



PI. XXXIII, Fig. 126 



Sertularia similis Clark, Alaskan Hydroids, 1876, p. 219. 



Sertularella nana Hartlaub, Hyd. aus dem Stillen Ocean, 1891, p. 361. 



Sertularia tenera Nutting, Hyd. from Alaska and Puget Sound, 1899, 



p. 743. 

 Thuiaria similis Nutting, American Hydroids, pt. 2, 1904, p. 69. 

 Thuiaria similis Fraser, West Coast Hydroids, 1911, p. 77. 



Trophosome. — Colony bilateral, with the main stem ■ very dis- 

 tinct and much stouter that the branches; branching regularly al- 

 ternate ; hydrothecae usually in nearly opposite pairs which vary much 

 in the distance from one another, although the distance may be fairly 

 constant in the same colony; hydrothecae slender, tubular, tapering 

 but slightly to the margin, distal portion free and turned well outward ; 

 sometimes they are much prolonged in which case they project for a 

 large portion of their length; margin with two distinct teeth; oper- 

 culum with two flaps. 



Gonosome. — Gonangia small, oval, narrowing more towards the 

 base than towards the margin; a short collar is present with a circular 

 aperture; the surface is free from spines and annulations. 



Distribution. — Bare Island (Hartlaub) ; Puget Sound, Albatross 

 Station 2865, N. 48° 12', W. 122° 49', 40 fathoms, Station 3465, N. 

 48° 21', W. 123° 14', 48 fathoms (Nutting); San Juan Archipelago, 

 Dodds Narrows, Departure Bay (Fraser) ; Rose Spit, Massett, China 

 Hat, Claninnick, Port Renfrew,- Nawhitti Bar, north of Cabriola 

 I., Northumberland Channel, Pylades Channel, Ruxton Passage, 

 Cabriola Pass, Gabriola Reefs, off Matia I., off O'Neale I., off Shaw I., 

 off Brown I., San Juan Channel, Deer Harbor, Upright Channel, Griffin 

 Bay, Port Townshend. 



In my West Coast paper I have called attention to the great 

 amount of variation of the species and the fact that Sertularella 

 nana Hartlaub is almost certainly one of these variations. I believe 

 further that the specimens described by Nutting from Puget Sound 

 as Sertularia tenera are also of this species. His figures pi. LXII, 

 fig. 1, A and B, certainly look much more like his figures of T. similis 

 in his monograph, pi. X, figs. 7 and 8, than they do like those of T. 

 tenera in the same work, pi. XI, fig 10. Colonies obtained from his 

 Puget Sound material bears out this indication. Whether his reference 

 to T. tenera in his Albatross material from the same or nearly the same 

 locality is of the same type I do not know. I have not found any 

 specimens of T. tenera in any collections from this region but 

 assuming that the Albatross reference is correct, I include T. tenera 

 in the list. 



