HYDROIDA. BALE. 279 



Further reference to these and other related forms will be 

 found under the description of the proposed genus Levinsenia, 

 all the species of which have six or more teeth on the 

 hydro theca-margin, and, so far as is known, no operculum. 



Loc. — Nuyts Archipelago, Great Australian Bight, 10 

 fathoms. 



Genus Thuiaria, Fleming. 



Thfiaria sinuosa. Bale. 



Thuiaria sinuosa, Bale, Proc. Linn. Soc. N.S. Wales, (2), iii.,. 

 1888, p. 772, pi. xviii., figs. 9, 10 ; Id., Bale, Biological! 

 Results "Endeavour," ii., 1, 1914, p. 12. Id., Ritchie, 

 Mem. Austr. Mus., iv., 16, 1911, p. 844, pi. Ixxxv.,. 

 fig. 4. Id., Levinsen, Vidensk. Medd. fra den naturh. 

 Foren, 64, 1913, p. 297. Id., Mulder and Trebilcock^ 

 Geelong Nat., (2), vi., 1914, p. 9. Id., Briggs, Rec. 

 Austr. Mus., X., 10, 1914, p. 294, pi. xxv., fig. 1. 



Though obviously belonging to this species the specimens 

 differ from the type in having the curvature of the hydro - 

 thecse very slight or, more commonly, entirely wanting. 

 The apertures are ill-defined, in consequence of the extreme 

 delicacy of the perisarc towards the margin. 



Locs. — Great Australian Bight, Long. 127° E., 100 fathoms. 



Shoalhaven Bight, New South Wales, 15-45 fathoms. 



Genus Sertularella, Gray. 



Though Levinsen's views regarding the genus Sertularella 

 are to some extent combated by Nutting and other observers, 

 who demur to admitting multiserial species (Dictyodadium),. 

 and admit some which Levinsen would exclude, there appears 

 to be practical unanimity regarding those forms which have 

 the characteristic three- or four-valved operculum and a 

 biserial and alternate arrangement of the hydrothecse ; even 

 when their division into long internodes supporting numerous 

 hydrothecae would bring them strictly within the limits of 

 the genus Thuiaria, as formerly understood. Such species, 

 included in the present collection, are Thuiaria lata and 

 Sertularella adpressa, which are certainly not, at any stage 

 of their growth, divided into single-celled internodes, the 

 feature which I have urged in Part I. should be regarded as 

 characteristic of the genus, from the point of view of the 

 colonial characters. Accordingly I now rank these forms in 

 the genus Sertularella, and this I consider tantamount to 

 admitting that all biserial forms with the characteristic 



