24 



SPONGES 



(c) Colour. — The colours of sponges are very varied, and often 

 very bright, especially in the case of species inhabiting the shore- 

 line, rendering them very conspicuous objects, and contributing 

 largely to tlie display of colours in the submarine scenery of caves 



Fio. 37. 



Efpcriopsis fhnllenqtri, R. (aftor 

 Kidloy)." J. 



Fio. 3S. 



Styloeordyla slipitata, Crtr. 

 (after Agassiz). §. 



-/'^''^v^^ -T-^ :\i~> :-^i 





Eusitoiujia officiiuUif, L. (after Schulre). J. 



and sheltered spots along the coast. INIany s{>onges, however, have 

 no special colouring-matter, and then are simply white or gray, the 

 prevailing tint amongst Calcarea. The littoral species of Domo- 

 spongiae, on the other hand, are usually brightly coloured, especially 

 in the Monaxonida and Keratosa, various shades of yellow, orange, 

 red, or lilac being the prevailing tints, but blue is not uncommon, 



