Australian Hydro I dx. 125 



Tlie precise form of the hydrotheca-margin is doubtful. In the 

 best -preserved specimens there is an angle in the middle of the 

 upper side, but no tooth, and the lower side is simply rounded, or 

 with two lateral lobes scarcely indicated. But so delicate is the 

 perisare at the margin that the shape seems in all cases more or 

 less altered. Even in the fresh specimens the condition seems 

 to have been similar, as Busk described the aperture as irregular. 

 In S. loculosa tlie perisare is stouter, and there is even a distinctly 

 thickfiied l)oi-(lci' to tlie aperture. Init tlii.s is wanting in S. fiir- 

 f)i/iiif(i, at least in these specimens. 



Whether the oblique nodes, which in S. Incidosa are found in 

 addition to the simjile transverse ones, ever occur in -S'. fitr/>/>iofa, 

 I eautiot say. Xont- exist in my specimens, wliich consisted 

 altogether of iibout sixty internodes, and Jaderholm, whose speci- 

 mens loiiL'spondLMl with Husk's figure, does not mention them. 



The gonangia are similar to those of S. locidosa, with, according 

 to Jaderholm, five or six annulations. 



The species appears to be rare. I have seen no examples other 

 tlian Busk's, thougluS'. loculosa is quite common in the same locality 

 (Bass Strait), and the only other record I have met with, besides 

 Lamouroux', is that of Jaderholm. Possibly »S'. locidosa is a 

 shallower-water form, and hence more often thrown on the beach. 



In considering the validity of the distinction which I have drawn 

 between these two forms it must be borne in mind that I have had 

 only the one mounted colony of S. turhinafa under examination. 

 It remains for future investigation to determine the relationship 

 between the two forms. 



Skutitlari.a MAH(4i\.vr.\ (Kirchenpauer). (Plate XII., Fig. 9.) 



Dj/naineii(i nKirrii nata. Kirchenpauer, Verli. d. K. L.-C. 



deutschen Akad. d. Naturf.. xxxi., 1804. p. \-\, figs. 



8-8c. 

 Sertularia fosridnx, D'Arcy W. Thompson, Ann. and Mag. 



N.H.. Ser. 5, iii., 1879, p. 104, pi. xvii., figs. 2-2a. 

 Sertularia amplectens, Allman. Journ. Lin. Soc, Zool., 



xix., 1885. p. 141, pi. xvi., figs. 3, 4; Jaderholm, Bihang 



till. k. svenska Vet. -Akad., xxi.. 1896, p. 13, pi. 



i., fig. 9. 

 Desmoscyphus r/racilis. Allman, ('hall. Kept., Part ii.. 1888, 



p. 71, pi. xxxiv., figs. 2-2c. 

 Desmoscirphus inflatus, Versluys, Mem. Soc. Zool. de 



France, xii.. 1899. p. 42, figs. 11-13. 



