74 Geology of St. Croix. 



tween this and the sea, there are at present two lagoons, and 

 also extensive beds of unstratified gravel, which have obviously 

 been washed down from the mountains, and contain large quan- 

 tities of shells belonging to the genera Helix, Caracolla, Bulimus, 

 and Pupa, which are now extinct upon this island, but are found 

 upon others in the neighborhood. I might adduce other evidence 

 bearing on the same point, but the limits of this article will not 

 allow. 



The beds of the ocean are lined with coral on every side of 

 the island, and, in many places, the reefs rise near the surfa(;e of 

 the water. This is particularly true on the south coast, and at 

 the harbor of Christian stad ; which is, indeed, with the excep- 

 tion of a narrow break that affords a passage for vessels, com- 

 pletely enclosed by a coralline bank. 



St. Croix contains but few minerals. Calcareous spar and arra- 

 gonite are the only two varieties which I saw. The latter occurs 

 in the form of small, parallel, combined columns, and of six-sided 

 prisms with re-entering angles on the sides. Both kinds are well 

 developed. 



Though the soil of the island was originally very productive, 

 it has been much impoverished by a long course of unvaried cul- 

 tivation. The elements however of an admirable soil still remain ; 

 and all that is necessary is to bring them into a suitable combi- 

 nation. Many parts of the island might be exceedingly improved 

 by an artificial admixture of the marl and clay ; and all need a 

 fresh supply of the nutritive principle of a vegetable compost. 

 The island of Barbadoes, which much resembles St. Croix, both 

 in the geological formations and in the worn state of the soil, has 

 been wonderfully revived by improved agricultural processes, and 

 especially by compost manures and a more frequent alternatixDn of 

 crops. I do not doubt that the productive powers of St. Croix 

 might be doubled in a few years by similar methods ; an object 

 certainly deserving the attention of the landed proprietors. 



