^38 ^' ^^^' ^^^^•* 



Sertularella Torreyi, Nutting, Bull. U.S. Fish Comm., 



1905, p. 949, pi. iv., fig. 4; pi. xi., figs. 2, 3. 

 Sertularella sjjeciosa, Congdon, Proc. Amer. Acad, of Arts 



and Sci., xlii., 1907, p. 476, figs. 24-28. 



Sertularella trideiitata, Billard, Ann. Sci. Nat., Zool. (9), 



ix., 1909, p. 312; xi., 1910, p. 14. Stechow, Hvdroid- 



polypen der jap. Ostkiiste, II., 1913, p. 137, figs. 111- 



113; (No. 17 Thuiaria sp., Inaba, Zool. Mag. Tokyo, 



1890, fig«. 46-48). Bale, "Endeavour" Report, Part 



III., 1915, p. 288. 



In the " Endeavour " Report I have referred to this species 



(under the name of S. tridentata) when dealing with S. lata, whicli 



had been confused with it, pointing out that the two species agree 



so closely as to be easily mistaken for one another in the absence of 



the gonosome. I had not then seen the species described by 



Billard as *S'. tridentata, but have since, through the kindness of 



.my friend, Mr. James Wilson, been furnished with fertile speci- 



imens collected by the Rev.< Dr. Porter at Moreton Bay, from which 



locality Busk's specimens, described by AUman as Thuiaria 



diaphana, were also obtained. 



In the above-cited paper are enumerated the main differences 

 T^etween the gonangia (which indeed are dissimilar in every par- 

 ticular), and L will only add that those of *S'. lata are very large 

 ^about 3.5 mm. in length), while those of the present species are 

 smaller, more delicate, and hyaline. They are not so symmetrical 

 as might be expected from the published figures, but apt to be 

 rather irregular, with the longitudinal plications sometimes dis- 

 tinct, but often faintly marked, and in some cases entirely Avanting. 

 But apart from the gonangia I found no difficulty in distin- 

 guishing the two species. It is true that many of the hydrothecae 

 intergrade, but on comparing typicaT specimens, and especially 

 the proximal portions of the pinnae, we find that in S. lata the 

 hydrothecae are closer together, are less divergent laterally, and 

 not turned so much to the front, and that the apertures are more 

 nearly vertical. In all cases the figures cited in the list of 

 ■fiynonyms agree in tliese particulars with the form before us rather 

 than with S. lata. The differences are doubtless no more than 

 might reasonably be expected to occur within the limits of a 

 fipecies, and okservers meeting with infertile specimens would 

 naturally associate them together. I have probably done this in 

 legard to certain specimens from Port Stephens, which I considered 



