THE BUH.DINO OF AN ISLAND. 39 



otherwise, to see how the form could have been so well retained as we actually 

 find it In any case, we have here a fossil of great interest and that may 

 possibly be of some value to geologists in helping to find the relation of our 

 St. Croix strata to those of other parts of the world. 



Fossil fragments similar to those described above are to be found in the 

 cliffs near to the ancient limestone rock at the estate St. John's, and also at 

 the estate Salt River, where they may be seen in some thin beds that cross 

 the main road. Besides the fossil remains above mentioned, the limestones at 

 all the places named contain foraminiferous shells, the section showing a 

 coiled shell with numerous chambers. . 



Conglomerates. 



Leaving the subject of the fossils, we may now turn to another interesting 

 question, namely, the occurrence of conglomerates in the blue-beach formation. 

 Prof. Hovey, in his notes alreatly referred to, remarks in reference to these 

 rocks " no conglomerates," and this must certainly have been correct for the 

 rocks he examined. The present writer, indeed, has not noticed any conglom- 

 erates among the rocks of the northwest, which appears to have been the part 

 examined by the professor; but has seen them in other parts of the island. 

 At the west end of Buck Island there is a bed of true conglomerate (' pud- 

 ding-stone "), that is to say, the pebbles are all thoroughly water-worn. In 

 other places may be seen conglomerates in which the embedded fragments 

 retain entirely or in a great degree their angular form, the stone belonging 

 more nearly, therefore, to what the Italian geologists called "breccia." De- 

 tached blocks of rock of this sort may be seen at Hermon Hill ; while at Salt 

 River Point there is a great mass of rock of similar character. The same is 

 true of the point projecting northward in the middle of the Salt River. At 

 Hermon Hill the blocks have evidently been broken off from a thick layer, 

 which, however, the present writer has not been able to locate ; but at the 

 two points mentioned no stratification can be made out, and the appearance of 

 the rock suggests that it has been a mass of debris, such as we now see spread 

 over our Central Plain, and has been subsequently hardened. Professor Cleve, 

 speaking of the St. Thomas rocks, says: "the occurrence of scoriaceous (cin- 

 dery) pieces in the conglomerate indicates its volcanic origin." Though not 

 seen by the present writer, it is not unlikelv that conglomerates of similar 

 character exist also in St. Croix. 



Travertine. 



Reviewing what we have so far learned in regard to the origin of the older 

 rocks of our island, we may say that we have seen that thev were formed from 

 debris of greater or less fineness, and most likely of ultimate volcanic origin, 

 brought down from an adjacent land by streams into the sea, formi-ng there 

 mud deposits and conglomerates arranged in definite layers, subsequently to be 

 altered to the hard rocks, which Professor Hovey describes as indurated clay, and 



