252 " ENDEAVOUR " SCIENTIFIC RESULTS. 



Hebella calcarata (in part), Billard, Arch. Zool. exp. et 

 gen., (4), vii., 1907, p. 339. Id., Ritchie, Proc. Zool. 

 Soc., 1910, p. 810. Id., Ritchie, Mem. Austr. Mus., 

 iv., 16, 1911, p. 816. 



Hebella calcarata, Nutting, Bull. U.S. Fish. Comm., xix., 

 1901, pp. 353, 378, figs. 56, 94. Id., Fraser, Bull. 

 Bureau of Fisheries, xxx., 1912, p. 371, fig. 34. 



Not Lafoea cylindrica, von Lendenfeld, Proc. Linn. Soc. 

 N.S. Wales, ix., 1884, p. 912, pi. xl., figs. 4-5. 



In my paper in the " Proceedings of the Royal Society of 

 Victoria "* for 1913 I have given reasons for concluding that 

 Pictet and subsequent observers were almost certainly wrong 

 in identifying H. scandens (Bale) with H. cylindrica (von 

 Lendenfeld), while suspending judgment with regard to its 

 identity with Hebella calcarata (Agassiz). Since then I have, 

 through the kindness of Dr. Fraser, received specimens of 

 H. calcarata, comparison of which with H. scandens shows 

 that the affinity between the two forms is even closer than 

 the published descriptions would seem to indicate. I cannot 

 resist the conclusion that (unless differences in the gonosome 

 should be discovered) they must be regarded as varieties of 

 a single species. 



The hydrothecae are quite similar, and I found a single 

 mature gonotheca of H. calcarata, which did not differ per- 

 ceptibly from those of H. scandens. The distinctions prac- 

 tically narrow themselves down to the unbranched habit of 

 the former, while H. scandens branches freely, and to the 

 frequent arrangement of the hydro thecse of H. calcarata in 

 opposite pairs, while those of H. scandens are always single. 

 The typical H. calcarata usually occurs on opposite-celled 

 Sertularians, and its general rule of growth (subject, how- 

 ever, to many exceptions), is that the creeping stem runs 

 up the front of the hydrocaulus of the host, and gives off a 

 pair of opposite or nearly opposite hydrothecse just above 

 those of the latter. H. scandens is mostly found on Sertularella 

 divaricata, and, when it makes its nearest approach to 

 regularity, gives off a single hydrotheca above each of those 

 of the Sertularella. It would appear reasonable to assume 

 that the difference is simply an accommodation to the habit 

 of the host-species ; I have, however, met with one or two 

 cases where the host was an opposite-celled Sertularian while 

 the hydrothecse of the Hebella were in no case opposite. 



On the other hand, I found on a specimen of Pasythea from 

 Bondi, New South Wales, a single colony which had the 



1. Bale Proc. Roy. Soc. Viet., (n.s.), xxvi., 1913, pp. 118-120. 



