Miscellaneous. 151 



The two zones which the seaweeds habitually occupy, the one at 

 the highest (Fucus vesiculosKs, F. serratus), the other at the lowest 

 {Laminaria) water, are clearly separated at RoscofF by HhnanthaUa 

 loreu, which is employed in the country as manure, under the name 

 oi filet, in the culture of vegetables. The zone of the filets is unco- 

 vered at the period of the sj'zygics ; but it is not entirely dry, except 

 at the greatest tides, when the Laminarire situated below it are like- 

 wise accessible. All these particulars are necessary ; for it is impos- 

 sible to form an idea of the difficulty of investigations among the 

 rocks covered withjilets, unless one has been in the midst of the long 

 bundles of viscous lashes of the Himantludia which conceal the 

 ruggedness of the stones and slip away under the feet. Nothing is 

 to be found among them ; and their examination is not only exces- 

 sively difiicult, but actually dangerous, from the continual falls that 

 one gets. 



In the Lamiuarian zone, investigation is at the same time easier 

 and more fruitful ; but what is of importance in the very peculiar 

 point of view now before us is the presence of Sargassum in this 

 zone, and the curious fact that this seaweed sometimes abandons the 

 deeps to ascend even to a considerable elevation, under circumstances 

 which it is important to indicate. 



At the time of the lowest tides, the sea, in retiring, hollows out 

 furrows in the sandy flats and in the marine meadows. The water 

 which flows from the parts which have emerged forms in these fur- 

 rows true rivulets, often of considerable size and rapidity. At the 

 west of the isle Verte, and of the Bourguignons, these erosions are 

 numerous ; and it is in the water which fills them that we see the 

 Sargassum rise high up, and that we find abundance of Pentacrinus 

 ewoijceus. If at the time of the spring tides we go to these streams 

 and detach large and tufted stalks of Sargassum, tearing them up 

 quite close to the bottom, and selecting the most branchy, we are nearly 

 sure, in the months of July and August, and the beginning of 

 September, to meet with Pentaceini. 



This search must be made as follows : — When plants of Sargassum 

 are very much branched, the branchlets interlace and form a sort of 

 bush, in the midst of which Antedon rosaceus particularly likes to 

 introduce itself and reside. It must be added that the Ascidia, the 

 Sponges, the Sertularia, and the Bryozoa are also so niimerous there, 

 that each plant of Sargassum would furnish a collection of itself. 

 The Antedon is there sometimes in such abundance, that it colours 

 the stems, by twisting its arms around them ; and as it occurs there 

 of all sizes, I thought the station a proper one for its develop- 

 ment, and set to work to find its Pentacrinus. My expectations were 

 soon realized, and I was able to collect, even on the beach, very fine 

 examples. But it is more convenient to carry away stalks of Sar- 

 gassum covered with Antedon, and to examine them by separating 

 the small branches under the lens and in water. T have thus found 

 Pentacrini of all ages. I have preserved them living for a long 

 time ; and those of the largest size, after having moved about and 



