from the Observations of himself and Mr. Clemson. 31 



Coral Rock of different Ages on the Shores of the Island of 

 Cuba. — In our examination of the rocks which approach the 

 north coast of Cuba, we have seen nothing to countenance the 

 hypothesis of a gradual transition from the crystalline white 

 limestone we have described in this article, to the fragmentary 

 coral rocks which appear on some parts of the coast, and 

 thence to the modern reef of living corals which encompasses 

 the Indian islands. Some such passage we have observed on 

 the borders of the sea near Matansas, the Havana, and the 

 Moro Castle; but the compact limestone of the first class is 

 not in those positions, and a newer lithographic rock inter- 

 poses. 



On the west side of the Bay of Gibara the white limestone 

 is observed, declining at first at an angle of 45°, and then de- 

 creasing to 20° towards the sea. Upon and near the base of 

 this slope rest ancient beds of aggregate coral rock, reaching 

 to about twenty feet above the present high-water line. This 

 rock is indurated and externally honeycombed like the white 

 compact limestone of the mountains. 



Three or four miles to the west of the bay the shore is 

 bordered with a reef of living corals, having an intermediate 

 space of shoal water called the Baxo, nearly half a mile broad, 

 between it and the beach. This shoal has been described in 

 detail by Mr. II. C. Taylor in Loudon's Mag. of Nat. Hist, 

 vol. ix. p. 449, &c. 



High up on the beach may be seen a more ancient reef, 

 forming a solid ledge of aggregate rock, for the most part 

 composed of corals, shells, and coral sand or mud, now conso- 

 lidated into a hard rock or cliff, some twenty or thirty feet 

 high, against which the surf beats violently at high water. 

 This is another proof of a change of level on this coast. The 

 old reef, of which we spoke, after continuing for a mile or two 

 as a cliff whose base is washed by the waves, passes obliquely 

 inland, and now has a hill covered with a thick wood of wild 

 fig, sea-grape, and a few aloes and palmettos between it and 

 the sea. This rock is also honeycombed, its surface being 

 full of holes and sharp points. In the mass, which consists of 

 various madrepores and cabbage-formed corals of great size, 

 we observed spines of Echini, and numerous univalve and bi- 

 valve shells, having their cavities wholly filled with indurated 

 coral, sand, or mud ; the whole forming a perfect illustration 

 of the consolidation of an old rock containing organic remains, 

 some of the oolites, for instance, the coral rag, or the Farring- 

 don coral beds. 



From this old reef we collected a series of characteristic spe- 

 cimens, all of which are common in the West Indian seas. One 



