130 Phosphate of Lime in the Mineral Kingdom. 



also as shewing the co-existence of certain saurian and molhiscous 

 forms at equal geological times. We have thus the modern croco- 

 dile or alligator (living probably much in the same way as the spe- 

 cies of the same genus do in the present day, namely, in rivers and 

 estuaries) borne into seas in which molluscs of the same kinds as 

 have their remains entombed in our cretaceous rocks, were living. 



From the general characters of the other saurians found we should 

 also infer that their habits were not such as to render the sea among 

 their usual haunts, but rather that they lived in rivers and estuaries, 

 occasionally coming .on the adjoining lands. When we look at the 

 lithological characters of the beds in which these remains are en- 

 tombed, as well as to the state in which the bones are preserved, it 

 at once becomes evident that they have been carried to the situations 

 at or near which they are now discovered, by being rendered specifi- 

 cally lighter than they now are, or formerly could have been. In 

 fact we seem required to consider that flesh was on the bones when 

 they were borne into the seas, amid the deposits and creatures living 

 at the time, in which they are detected. However dificult it may 

 be to wash crocodilian animals into the adjoining seas from out 

 many of the great rivers of the world where these creatures live in 

 multitudes, more particularly where mangrove swamps abound at 

 their embouchures, this is not the case with tlie short torrent rivers 

 descending from liigh lands into the seas surrounding islands, as, for 

 instance, Jamaica and Hayti. During a great flood in the Yellahs 

 river, one which takes its rise in the Blue Mountains of Jamaica, 

 and at whose mouth and in the adjoining mangrove swamps the 

 caimans are common, the body of water was so great as to sweep 

 these crocodilians off to sea, where it may be presumed some 

 perislied, to leave their bones, at least such as were not swallowed by 

 the large fish, to be mingled with the remains of marine molluscs 

 now living in those seas. In cases of Hoods of this kind, the sudden- 

 ness of which can be scarcely appreciated by those who have not 

 witnessed the waters of heavy tropical rains dLvcharged by means of 

 a short steep course from high mountains into the sea, many a river 

 and estuary air-breathing creature gets overpowered and carried off 

 before it can reach the protection of eddies near the banks; and 

 should there be a heavy sea going at the time, as sometimes happens 

 when a hurricane is accompanied by floods of rain, there is a poor 

 chance of their escape from di owning, however well fitted for living 

 in rivers and estuaries under ordinary con<litions. 



5. Phosphate of Lime in the Mineral Ivingdom. — The agricul- 

 tural importance of phosphate of lime has of late years caused more 

 search to be made for this substance than formerly, though its oc- 

 currence, as a component part of certain organic remains and of some 

 rocks, has been long known. ^Ir Paine, of Farnham, having pointed 

 out that certain beds contained phosphate of lime in sufficient abun- 



