126 Memoirs of the Indian Museum. [Vol. V, 



Division VESICULARINA. 



Family Vksicularidae. 



Genus BOWERBANKIA, Fane. 



Bowerbankia caudata, Hincks. 



1880. Bowerbankia caudata, Hincks, Brit. Marine Polyzoa, p. 521, pi. lxxv, figs. 



7-8- 

 1880. Bowerbankia gracillima, id., ibid., p. 525, pi. lxxv, fig. 6. 



1907. Bowerbankia caudata, Thornely, Rec. Ind. Mus. I, p. 196. 



1908. Bowerbankia caudata race bengalensis, Annandale, Rec. Ind. Mus. II, 



P- 13- 



1911. Bowerbankia caudata subsp. bengalensis, id., Faun. Brit. Ind., Freshw. 

 Sponges, etc., p. 189. 



In the form I have named bengalensis the zooecia show every gradation between 

 those of B. caudata and those of B. gracillima as figured by Hincks, and sometimes 

 even surpass the latter in their elongation and relative slenderness. They also vary 

 in colour, sometimes being quite hyaline and sometimes having a rather opaque 

 brownish tinge. Generally speaking, the zooecia of young or poorly developed 

 colonies and of the younger parts of more luxuriant ones are short, relatively stout, 

 colourless and transparent, while those of more opulent colonies are longer and rela- 

 tively more slender ; it is only some zooecia that become darkened. I have found 

 none in which the " tails' formed branching radicles, but occasionally they are 

 forked. The racial name bengalensis can hardly be maintained in view of the varia- 

 bility of the form to which it was applied. 



Waters l has pointed out that at present it is hardly possible to identify some 

 of the supposed species of Bowerbankia and that the " tailed ' condition of the 

 zooecia is by no means confined to Hincks' s caudata. The Indian form, however, is 

 constant in its method of growth, except in so far as it is indicated above, and never 

 produces upright or hanging branches. The gizzard {i.e. the part bearing horny 

 teeth) is about 0-058 mm. in transverse diameter when expanded, the length in this 

 condition being considerably less than the breadth, viz. about 0-046 mm. According 

 to Waters (op. cit., p. 242) the diameter of the organ is about o-i in B. imbricata cf in 

 an ordinary non-inflated condition." The anatomy of the polypide agrees closely 

 with that of a specimen from the Irish Sea (Port Erin) lent me by Mr. F. H. Gravely, 

 in particular in the structure of the gizzard. The figure of this organ reproduced 

 on pi. xii, vol. VI of the Records of the Indian Museum (191 1) for comparison with 

 those of Victorella and Hislopia was drawn from Mr. Gravely' s English specimen. 



B. caudata, to judge from the few references* in literature to it, seems to be a 

 scarce species in European waters. In India I have seen it only in the neighbour- 



1 I own. Linn. Soc. (Zool.) XXXI, p. 241 (1910). 



2 For references see Waters, op. cit., pp. 248, 249. Most of the works he cites are unfortunately 

 not available in Calcutta. 



