Mr. H. J. Carter on the Parasites of the Sjwnges. 331 



filaments, wliicli have a cell at one end and a spiral twist 

 throughout, admits that they are different from the sponge- 

 cell j9ar ea;ce?/e7ice {i. e. the sponge-animal), and after alluding 

 to KoUiker's doubt in 1866, viz. whether it be a part of the 

 sponge or a parasite, agrees in 1870 (Atlantisch. Spong. Faun.) 

 with Kolliker, that the two structures, viz. the sponge-fibre 

 and the fibrillse, are different, finally ending with the expres- 

 sion that, after much trouble, he can state nothing further 

 respecting the nature of the latter. 



In his critique on the synonymy and species of the Kerato- 

 spongia, in 1864, Schmidt observes, respecting Auliskta, that 

 Dr. Bowerbank's illustration of his so-called " compound 

 fistulose keratose fibre" in this genus {I. c. pi. 14. fig. 268, and 

 Annals, 1. c. pi. 13. figs. 1 & 2) proves that it is nothing more 

 than an " Alga," and therefore, being no genus at all, that the 

 name should be expunged. I came to the same conclusion 

 before finding that Schmidt had done so ; but am not sure 

 whether the branched filament is part of the mycelium of a 

 Mucor, or an Alga allied to PytMum entopliytum among the 

 Saprolegniese. Many genera of the Mucedines, especially 

 BotrytiSj infest the Sponges; but I have not yet, to my know- 

 ledge, seen one Saprolegnieae. Dr. Bowerbank's illustrations 

 of his so-called " fibrillated sponge-fibre " of the " Australian 

 sponges " (/. c. pi. xvi. figs. 280 & 279) are also of the same 

 kind. In short, no tortuous branched fibres of the sort are 

 proper to the Spongiad^e ; and hence all genera based upon 

 them should be suppressed. 



The "East-Indian Sponge," too [I.e. pi. xx. fig. 307), 

 which Dr. Bowerbank gives in illustration of the " inhalant 

 areas " in this species — Dr. J. E. Gray has correctly stated 

 (Proc. Zool. Soc. May 1867, p. 514) that the latter are nothing 

 more than polypes, " probably a parasite like the genus Bergia 

 of Michelotti." But I do not wonder at Dr. Bowerbank's 

 mistake here, when, in the figure 374 following, he represents 

 the polypes of Hyalonema as the " oscula of a columnar cloacal 

 system" (!). 



Of such parasitic polypes there is one which is entirely iso- 

 lated, another which is concatenated by a stoloniferous pro- 

 longation of the })olypidom (viz. that figured by Dr. Bower- 

 bank as " inhalant areas "), a third in groups, as in Schmidt's 

 Palythoa on the sponge Axinella, and a fourth in a con- 

 tinuous polypidom entirely surrounding the glass rope of 

 Hyalonema. 



It seems to me absolutely necessary that, if any one would 

 describe a sponge with accuracy, he should be generally ac- 

 quainted with all, or at all events with most of the known 



25* 



