178 CORALS AND CORAL LS LANDS. 



Exuma, and elsewhere ; but the spherules are solid, and have 

 been derived apparently from the stems of corallines. . . . 

 A chalk-deposit is to be found, by all accounts, in the different 

 basins or lagoon bottoms in every principal group, though 

 nowhere so extensively as along the western coast of Andros 

 Island, where it may almost be termed a young chalk forma- 

 tion. . 



" The ' red earth ' previously mentioned as forming, generally 

 speaking, the scanty soil of the Bahamas, is at times interstra- 

 tified with the rock, and sometim.es it is incorporated with it. 

 It is identical with the ' red earth ' of the Bermudas (specimen 

 No. 15) which proved a considerable source of embarrassment, 

 especially with reference to Ireland Island, by seeming to point 

 out alternations of aqueous and other deposits, which were con- 

 tradicted by the presence of the characteristic Jle/ix in all the 

 beds. In visiting a cave near Delaport in 1849, Capt. Nelson 

 found the bottom of the cave for many feet in depth covered 

 with a loose dry ' red earth,' in grains varying in size from 

 coarse sand to fine dust (specimens 14 and 14 a, b). Under 

 the microscope this appeared as a mass of insect-remains, the 

 rejectamenta of bats living in these caverns. Specimens of the 

 earth from another part of the same cave, however, were so 

 much altered in character, that they resembled the Bermuda 

 ' red earth,' and afforded a complete clue to the characters of 

 this substance. Some of the varieties from the Delaport cave 

 were examined microscopically and chemically by Professor 

 Quekett, of the Royal College of Surgeons, who not only 

 confirmed the above, but announced that all the varieties gave 

 off ammonia, whether retaining organic texture or not. The 

 author thinks it not unlikely that the ' red earth,' even in the 

 case of the five strata in Ireland Island, has been largely 

 derived from bats inhabiting once-existing caverns ; at the same 

 time, he considers it probable that birds, their droppings supply- 

 ing a sort of guano^ have also assisted in the formation of 

 this deposit. 



" The occurrence of pumice floated ashore at Wading Island, 

 and elsewhere in the Bahamas, is briefly noticed." 



