262 



THE ZOOLOGIST. 



I am not prepared to admit, however, that L. insignis and 

 L.juncea are identical, for in the hydrotheca alone characters 

 exist apparently sufficient to distinguish the two forms. Thus, 

 while L.juncea has a hydrotheca shaped like the bowl of a clay 

 pipe, with an almost straight abcauline and a strongly humped 

 adcauline profile, L. insignis has an almost symmetrical hydro- 

 theca, with both abcauline and adcauline profiles nearly straight. 

 In the former, again, the proximal portion of the hydrotheca 

 narrows suddenly in forming the peduncle ; in the latter the 

 transition from hydrotheca to peduncle is very gradual, the 

 hydrotheca tapering gently from rim to base. Again, while in 

 L.juncea the rim is bordered by a double line (Pictet),* in those 

 hydrothecEe of L. insignis which I have examined only a single 

 line is present, the thickened band of chitin lying exactly along 

 the border of the cup, while in the Ceylon species it lies well 

 within the margin. 



Some difference seems to occur in the gonangia also, for 

 while Congdonf figures for L. insignis both furrowed and smooth 

 gonothecse, scarcely any of which exceed the length of the hydro- 

 thecae, Miss Thornely's figures of L. juncea show that the gono- 

 thecse are considerably larger than the hydrothecse, " about one- 

 third as long again."]: Pictet's figures, on the contrary, make 

 the gonangia of L. juncea shorter than the hydrothecae. 



It seems improbable, therefore, that L.juncea andL. insignis 

 are synonyms, but there can be no doubt that Campanularia in- 

 signis, Allman, 1888, is identical with Obelia marginata, Allman, 

 1877. The distinctions pointed out by Allman § are insignificant. 

 Indeed, the inverted cone shape which he attributes to the 

 hydrothecse of the latter describes exactly those of the former, 

 while the " annular segment between the peduncle of the hydro- 

 theca and its supporting internode " — characteristic of Campanu- 



* Pictet, C, 1893, "Etude sur les Hydraires de la Baie d'Amboine" 

 (Rev. Suisse de Zool. T. i. p. 37). 



f Congdon, E. D., " The Hydroids of Bermuda" (Proc. American Acad. 

 Arts and Sc. vol. xlii. No. 18, p. 46.7, figs. 10 and 12). 



I Thornely, L. R., " On the Hydroida." In Report on the Pearl Oyster 

 Fisheries of the Gulf of Manaar, by Prof. W. A. Herdman, F.R.S., Suppl. 

 Rep. vol. viii. Royal Soc. London, 1904, p. 114, pi. 1, figs. 1, 1a. 



§ Allman, J. GK, 1888, "Report on the Hydroida " (Scientific Res. « Chal- 

 lenger,' Zool., vol. xxiii. p. 19). 



