Australian Hydro Ids. 91' 



Tlie pieseiK'L' on soiiir of {\\v a])o]>liyses of a sarc-othera, or a pair 

 of tlieiii. was not iiiciil ioiied in tlie original description, having 

 Iteen overlooked by nie. an omission wliich is accounted for by the 

 fact that they are only present in a small jd'opoi'tion of cases, and 

 that rliey are so small as to he readily passed over, especially 

 as they are mostly below the axillary apophyses, where they are 

 more apt to be obscured. In fact, I could only find three or four 

 on the pinnae. In a few other instances marks were visible where 

 they had been detached, but for the most part even these were want- 

 ing. These little calycles are not unlike the hydrothecae in shape,, 

 but not narrowed at all towards the end. 



Thyroscyphus mauginatus Bale. 



Campanidaria marginafa. Bale, Cat. Aust. Hydr. Zooph.,. 



1884, p. 54, pi. 1, fig. 2; Proc. Lin. Soc. N.S.W. (2),. 



iii., 1888, p. 758. Bartlett, Geelong Nat., (2) iii., 1907, 



p. 62, fig. — . 

 " Camijaindnrla '^ niarginata, Levinsen, Vidensk. Medd. 



fra den naturh. Foren, 64, 1913, p. 289. 

 This species, which on account of its possessing hydrothecae with' 

 a four-valved operculum, I now refer to the genus Thyroscyi^hus, 

 is nevertheless of peculiar hal)it, differing from that of the otlier 

 known members of the genus. In its simplest form it consists of 

 a single hydrotheca, J)orne on a peduncle two or three times its own 

 length, which may have, near tlie base, a few irregularly-placed 

 joints; it therefore differs little in habit from such species as 

 Orthopyxis calicidata. But most commonly this structure is re- 

 peated two or three times, and in each case the new peduncle is 

 given off kterally from the preceding one, immediately below the- 

 summit of the latter, on which the hydrotheca is borne. The distal 

 end of the peduncle is usually a little curved, and the next peduncle 

 springs from the outer side of the curve. The curves do not usually 

 alternate; frecjuently two or thi-ee in succession are directed to 

 the same side. Occasionally two new peduncles spring side by side 

 from the preceding one. 



In the original description I mentioned that I had only seen the 

 operculum in a fragmentary condition, and so delicate is its nature 

 that I have not, up to the present, seen a perfect one. However, 

 I have specimens sufficiently well preserved to show that the oper- 

 culum is of the type which characterises the genus Thyroscyphns. 

 In some instances all trace of the opeiculum had disappeared, al- 

 though the hvdranths still survived. 



