HYBROZOA RITCHIE. 843 



Sertularella nodidosa, Calkins, Loc. cit., p. 360, pi. 5, fig 29. 



Station 57. 



With hesitation I refer two nainute colonies to this species. 

 The larger consists of a hydroihizal tube from which a stem, 

 11mm. high, springs. The stem is slightly geniculated and is 

 divided into, long slender internodes, at the distal end of each of 

 ■which a hydrotheca is borne. The hydrothecse resemble those of 

 Sertidarella polyzonias in general shape, but they have only three 

 marginal teeth. The salient characters may be summarised 

 thus : — Hydrothecse adnate for less than one half of their length 

 to the stem, the free portion being strongly exserted, projecting 

 from the stem abruptly almost at a right angle, and narrowing 

 to the orifice. The abcauline wall is straight, and occasionally 

 slightly waved, but the adcauline is marked by several definite 

 undulations. The apertures are obscured by the presence of very 

 many reduplicated margins, but they show that the hydrothecse 

 are furnished with three teeth and that intrathecal teeth are 

 absent. 



In all these respects our specimen agrees with Hartlaub's 

 description, and it also bears close resemblance to the figure 

 givein by hiiu (1901, pi. iii., fig. 21) of a specimen from Bare 

 Island, Vancouver ; and to that given by Nutting (1904, pi. xxii., 

 fig. 3). 



The greater length of the internodes and the straighter profile 

 of the hydrothecae in our specimens bring them into line with a 

 Japanese specimen described hj Nutting (1901, p. 95). 



It seems legitimate, therefore, to consider that our specimens 

 fall within the bounds of a species which is " by far the most 

 ivarirtble on the [CalifornianJ coast" (Torrey, 1904, p. 29), 

 although, owing to the absence of the gonotheca, which is char- 

 ^.acteristic, absolute identification is inadvisable. 



Dimensions. — 



Stem, diameter 0-18-0-21mm. 



Length between hydrothecse 1-20-141 ,, 



Hydrotheca, length free 0-36-0-49 ,, 



,, adnate 0-32-0-38 „ 



„ diameter at mouth ... lS-0-22 ,, 



Locality. — Station 57, off Wata Mooli, three and a half to four 

 miles from shore, 59 to 56 fathoms ; bottom, mud ; 22nd March, 

 1898. 



The species is new to Australian seas. It has hitherto been 

 ■ recorded only from the Pacific Coast of North America — from 



