Mr. H. J. Carter on Parasites of the Spongida. 157 



XVIII. — Parasites of the Spongida. 

 By H. J. Carter, F.R.S. &c. 



In 1871 ('Annals,' vol. viii. p. 330) I stated that I hoped 

 soon to communicate an " illustrated paper on the parasites 

 of sponges ;" and now, after having examined all the speci- 

 mens of the latter in the collections of the British Museum 

 together with those belonging to the late Dr. Bowerbank, and 

 with my own experience of the living sponges here (Budleigh- 

 Salterton) , I propose to notice those parasites which have come 

 under my observation and of which I possess specimens, being 

 well aware that there must be many more which have not been 

 discovered, or, if discovered, have not been made public. 



For illustrations I prefer figures which combine that of the 

 sponge with that of the parasite; and therefore reference will be 

 made to these whenever possible, while the rest hardly require 

 any; so that the only illustration that I shall insert will be one 

 of Spongiophaga communis^ which will be given in a woodcut 

 opposite the description. 



Crustaceans. 



It seems not uncommon for small Amphipod Crustaceans 

 about 1-1 2th inch long to nestle in the surface of some sponges, 

 where they make little oval depressions to lie in, more or less 

 bent upon themselves, which depressions, in the absence of 

 the crustaceans, may sometimes be taken for vents. This was 

 first noticed in Suherites anfarcticus, MS. (a branched Su- 

 berite of a grey colour, with large and almost spherical head 

 to its pin-like spicules, dredged up by Sir J. Ross in 300 

 fathoms in 77^° south latitude), and the crustacean kindly 

 described and illustrated by the Rev. R. R. Stebbing, M.A., 

 under the provisional name of Dexamine antarctica (' Annals,' 

 1875, vol. XV. p. 184, pi. xv. fig. 1, &c.). Similar depres- 

 sions with a smaller crustacean of a like form were afterwards 

 observed on the surface of a large mouse-coloured, areniferous, 

 estuarian variety of Suherites domuncula, Nardo, = Halichon- 

 dria suherea^ Johnston, on a Buccinum containing a Pagurus^ 

 probably from the Firth of Forth, Scotland, and, lastly, 

 though of larger size, on a living specimen of Halichondria 

 incrustans from this place (Budleigh-Salterton). 



Crustaceans are commonly found in the cloaca and half- 

 way through its aperture in Grantia ciliata and G. compressa, 

 especially towards the maturity of the gastrula, which, being 

 free from spicules and rich in nutriment, they devour greedily, 

 not refusing portions of the sponge itself ; so that, in gathering 



