1864.] J. M. JONES ON OCEAN DRIFTS. 43 



slime. In some situations it grows short and bushy, while in 

 others its stems are elongated to some extent. There are three 

 varieties of this species : (1,) with the cells greatly protruding ; (2,) 

 with the cells nearly even ; and (3,) having them strongly depress- 

 ed. There are two species of Meandrina found on these reefs, — 

 M. cerehra, commonly known as brainstone from its singular 

 appearance, and another species clearly different from the preced- 

 ino-, and allied to 31. Dcedalea of the Indian Ocean. The Madre- 

 jpora cerehra grows to a large size, sometimes three feet in diame- 

 ter, and is usually rounded in form ; while the latter is rarely found 

 more than six inches across, and growing in some cases within a 

 foot of the surface on reefs, and in rock-pools even less. Two 

 species of Astrcea occur, sometimes covering the rock like a mass 

 of sponge. These astroid corals are frequently found in a semi- 

 fossil state, imbedded in the reef, and forming the base of masses 

 of living madrepores. 



On breaking into one of the reefs left dry at lowest tide, you 

 find it composed of the following : the hard compact interior of 

 calcareous rock, exhibiting under the lens a mass of minute por- 

 tions of shell, sand, and broken coral, mixed with particles of 

 pink-colored nullipores ; the exterior presenting an irregular honey- 

 combed appearance, some of the recesses containing sea-water and 

 dotted with small specimens of the frilled Meandrina and small- 

 eyed Astrcea, and adhering to the sides of these miniature pools 

 several species of corallines and algce shooting out from beds of 

 scarlet, and sober-colored sponges and ascidians, over which 

 crawl the slug-like forms of the many-spotted Doris and sea-hare 

 (Apli/sia), and the msiss,i\e sheW-hesiY'mg Purpura deltoidea ; while 

 in the crannies and sinuous passages are snugly ensconced numbers 

 of purple Echini and hair-clad annelides ; the whole more or less 

 covered with a mantle of iridescent sea-weeds. 



Such is the state of affairs on the reef: now let us proceed to 

 take a survey of the productions, animal and vegetable, brought 

 thither by the current of the Gulf Stream. 



As before remarked, the marine fauna of the Bermudas is al- 

 most wholly West Indian. The first, if we except a few transient 

 visitors, are all found in the Carribean Sea. The mollusks, with 

 one exception only, according to Tristram, are all inhabitants of 

 the same district, while the remaining invertebrata of all orders 

 present a similar state. Many fishes are brought to the group, 

 sheltering and feeding amid the vast fields of gulf-weed (^Fucus 



