426 THE DEPTHS OF THE SEA. [CHAP. vir. 



an additional note on the habitat of Hyalonema lusi- 

 tanicum. It appears that the fishermen of Setuhal 

 frequently bring up on their lines, from a consider- 

 able depth, coils of silicious threads closely resem- 

 bling those of the Japanese species, which they 

 even surpass in size, sometimes attaining a length of 

 about 50 centimetres. The fishermen seem to be very 

 familiar with them. They call them ' sea-whips,' 

 but with the characteristic superstition of their class 

 they regard all these extraneous matters as ' unlucky/ 

 and usually tear them in pieces and throw them 

 into the water. Judging from some specimens in 

 the British Museum, and from Senhor du Bocage's 

 figure, the 'glass-rope 5 of the Portuguese form is 

 not so thick as that of H. sieboldi. There is also 

 some slight difference in the sculpture of the long 

 needles, but the structure of the sponge and the very 

 characteristic forms of the small spicules are identical 

 in the two. I doubt if there be more than varietal 

 distinctions between the two forms ; and if that be 

 so, it adds another to the list of species common to 

 our seas and the seas of Japan. 



Perhaps the most singular circumstance connected 

 with this discussion was that all this time we had 

 been looking at the sponge upside down, and that it 

 had never occurred to anyone to reverse it. We had 

 probably taken this notion from the specimens stuck 

 in stones, brought from Japan, and the sponge cer- 

 tainly looked very like the base of the edifice. When- 

 ever the sponges were dredged on the coasts of Europe 

 and compared with allied things, it became evident 

 that the whisp was an organ of support passing out 

 of the lower part of the sponge, and that the flat, 



