BY W. M. BALK. 751 



EUCOPELLIN^. 



EucoPELLA CAMPANULARIA, von Lendeiifeld. 

 (Plate XIIL, figs. 9-15). 



This hydi'oicl is no less remarkable for the structure of the- 

 trophosome than for the nature of the medusan gonozooid. I 

 received portions of two gatherings, both from Bondi, but 

 differing considerably in the form of the hydrothecse. The 

 bydrorhiza is remarkably broad, with a much thickened perisarc, 

 giving off branches at right angles. The peduncles^ which vary 

 from the length of a hydrotheca to four or five tiniPS as long, 

 are straight, and very thick and massive ; but the perisarc is 

 thinned away at the base down to its junction with the hydro- 

 rhiza, at which point the external diameter of the peduncle is but 

 little more than that of the cavity which runs through it. The 

 peduncle is rounded off at its summit, at which part the cceno- 

 sarcal tube is somewhat enlarged^ as it is also at the base. A 

 single spherule intervenes between the hydrotheca and the 

 peduncle. 



The hydrothecse ai-e remarkable among the Campanularians by 

 their bilateral symmetry Those of the variety which corresponds 

 most closely with the type specimens are, as seen in their broader 

 diameter, semi-ovate, with one of the narrower sides cut down a 

 little lower than the opposite one, and the broader sides elevated. 

 The margin is not everted nor toothed. There is no cavity 

 corresponding to the external shape of the calycle, but the 

 interior is tilled up with a solid chitinous mass, leaving only a 

 wide shallow depression at the top, and a narrow tuVmlar passage 

 to the base of the calycle. The hydranth is therefore not 

 retractile, but rests on the calycle, which furnishes a slightly 

 concave support for it. The solid pait of the calycle is clear 

 and transparent, yellowish in colour, and almost liomogeneous. 

 In the other variety the calycles are similarly solidified, but the 

 lower part appears as if condensed and shrunken ; and the trans- 

 pareiit homogeneous structure has given place to a woody-looking 



