Dr. J. E. Gray on Kuplectella speciosa. 139 



position in the sea. Sometimes more than one crab is found in 

 the cavity of the same sponge ; and I think I can determine, 

 through the network of the sponge, that they belong to different 

 species, or even genera : one looks much like a Pagurus. 



I am by no means sure that this is a correct explanation of 

 the form ; for it is exceedingly difficult to reason a priori on 

 such subjects ; and I only throw it out as a probable explanation 

 of the peculiarities of the form. 



A specimen in Mrs. Gray^s cabinet is interesting as showing 

 that the sponge has the power of repairing an injury. There 

 has evidently been a hole made in one of the sides, about the 

 middle of the distance between the base and the apex ; and the 

 animal has repaired the injury by forming a new network of 

 bundles of fibres very like the original structure. 



The specimens vary considerbaly in the convexity of the net- 

 work that closes the cavity, and also in the size of the spaces 

 between the network : in some the interlaced bundles of fibres 

 are broad, and the interspaces large ; in others the spaces are 

 small, and the interlaced bundles of fibres narrower and more 

 numerous. 



Mr. Wright has just informed me that there is a block of 

 timber in Germany which has ten specimens attached. This is 

 interesting as showing how they probably grow under the sea ; 

 and if they grow so grouped together, this explains why they 

 have come to Europe in such comparative abundance. 



The first specimen that Mr. Cuming had he sold for £30 ; 

 he bought it back for the same sum, and it came with his 

 collection to the British Museum. The first new specimens 

 that arrived sold for £10 or £15 each; they are now selling at 

 from £3 to £4 each. 



The specimens that first arrived were in their natural state as 

 taken out of the sea, and are of a pale brownish colour ; but 

 those that are now in the market have been cleaned and bleached, 

 which makes them more attractive to the unscientific purchaser. 



I have seen one specimen which is nearly cylindrical, being 

 scarcely broader at the upper end than a little above the base. 



Two specimens which have lately arrived are almost entirely 

 destitute of any frill round the upper end of the sponge : one 

 has a nearly regular, almost circular end, covered with very fine 

 reticulations without any apparent centre ; the other has an ob- 

 long aperture to the tube, which is produced at the edge on 

 the convex side of the curve of the tube, and it is covered with 

 very fine reticulations which seem to converge to many points. 

 This specimen is short, stumpy, and only slightly curved; 

 whereas the other is very much curved, so that the whole sponge 

 forms rather more than half of a circle. 



10* 



