40 RAMBLES OF A NATURALIST. 



whose conglomerated masses exhibit the colours and 

 translucence of the agate. The smoother stones 

 were all covered with Compound Ascidians, which 

 were spread over the surface in shining green, brown, 

 red, or violet patches, interspersed with markings 

 of geometrical regularity, which severally indicated 

 the different family groups of these singular beings. 

 Among these animals, all of which belong to the 

 great division of the mollusca, appeared thousands 

 of zoophytes, while Star-fishes of the finest carmine, 

 and grayish-brown Ophiuras, with their five long and 

 slender arms, lay hidden beneath the stones. Above 

 them the Flustra spread out its little stony weft, 

 Sertularias and Campanularias raised aloft their ar- 

 borescent polyparies, resembling miniature shrubs; 

 while the Eschara threw its microscopic cellules over 

 the stems and fronds of the marine plants.* Sponges 

 of every form and colour were intertwined among 

 the branches of the fucus and attached to the sides 

 of the rocks, either in thick masses or in interlacing 

 meshes of delicate network. Here and there the 

 Thetyaf might be seen, with its rounded lobes brist- 

 ling with little spicula, side by side with the finger- 

 like masses of the Alcyonium and the LobulariaJ; 



* The Flustra and Escharce, which were long regarded as 

 zoophytes, are now considered as Polyzoa, belonging to the class of 

 the Bryozoa. The Sertulariae and the Campanularige are zoophytes. 



f The Thetya is a kind of sponge having a globular form and a 

 compact structure. This group, which is very imperfectly under- 

 stood, has been made the subject of profound investigation by 

 M. Valenciennes, who, however, has not yet published the result of 

 his observations. 



\ The Alcyonium and Lolularia are polypes living in colonies 

 upon one common mass. 



