WEST COAST HYDEOIDS 77 



W. 167= 53', 13 fathoms: Stetion 3540. X. 56= 27'. W. 166= 08% 

 51 fathoms (Xutting). 



THUIAEIA riMILIS (Clark) 

 PI. VIII, Figs. 1-6 



Sertularia similis Clark. Alaskan Hydroids. 1S76. p. 219. 



Sertularia similis Hartlaub. Hydroiden aus dem Stillen Ocean. 1891. p. 

 362. 



Sertularella nana HARXLArB, Hydroiden aus dem StDlen Ocean. 1891. p. 

 361. 



Sertularia similis Xuttixg. Hydroids of the Harriman Ex.. 1901, p. 185. 



Sertularella nana Xuttixg. American Hydroids. Part II. 1904. p. 105. 



TTiuiaria similis Xuttixg. American Hydroids. Part II. 190-1. p. 69. 



Distribution. — Hagmeister Island (Clark' : Berg Inlet. Glacier 

 Bay, Puget Sound. Albatross Station 2842. X. 54= 15', '^. 166 = 

 03', 72 fathoms: Station 2865, X. 48= 12'. W. 122= 49', 40 fath- 

 oms; Station 3465. X. 48° 21', W. 123= 14'. 48 fathoms: Station 

 3515. X. 59= 59'. W. 167° 53'. 13 fathoms: Station 3557. X. 57 = 

 04'. TT. 170= 24'. 26 fathoms (Xutting : San Juan Archipelago. 

 Dodd's Xarrows, Departure Bay. 



This species is very common in the Puget Sound and the Van- 

 couver Island region, where it shows a very great degree of varia- 

 bility in the arrangement of the hydrotheciie. and in the shape 

 of these as well. In the t^'pieal arrangement on the branches, 

 the hydrothecfe are in nearly opposite pairs, being quite close to- 

 gether, but in some cases there is a long interval in each case, 

 while the arrangement may be still opposite or in extreme cases 

 it may become distinctly alternate, so much so that if it were not 

 for the intergrading specimens, one might t^ke it as a distinct 

 species as Hartlaub has evidently done when he describes it as 

 Sertularella nana. This has been copied by Prof. X^'utting, 

 though he indicates that he does not think it can belong to the 

 genus Sertularella. The entira range may be found in the same 

 colony, consequently, it is scarcely possible to apply both names 

 satisfactorily. The shape of the hydrothecje themselves, is as 

 variable as the arrangement, principally in the extent of their 

 elongation. Some of them are so much lengthened as to become 

 twice the normal length or more, so that they appear as long 

 regularly bent tubes. These elongations occur in what appear 

 to be old colonies, generally those acting as hosts to other hy- 

 droids. It may possibly be a diseased condition. 



