15 



Nitrogenous. 



Guanos > Phosphatic, or "leached." 



) Bat Guano. 



\ Bone beds. 

 Animal remains /• Shell beds. 



I Animal exuviae. 



We will now proceed to trace in a cursory way the commercially 

 known deposits, commencing with the most recent, and passing 

 stratigraphically in descending order to the more ancient formations. 



GUANOS. 



Guanos are of two kinds — Nitrogenous or those containing their 

 original manurial qualities, and phosphatic or "leached," the latter 

 being in a more or less mineralized condition by exposure to 

 weathering. 



Among the Nitrogenous guanos, we have the Peruvian, Ichaboe, 

 Patagonian and Falkland Islands. 



The phosphatic or weathered guanos include those of the Pacific 

 or Polynesian Islands, Sidney, Phoenix, Starbruck, Baker, Rowland, 

 Jarvis, Enderbury, Maiden, Lacep-.^de and Arbrohlos Islands. 



Some of these deposits are more or less exhausted, and new Islands 

 furnishing similar products are from time to time worked. 



The West Indian guanos are from Aves, Mona, Tortola. 



Other South American are Patos Islands, Mcgillones, Rata. 



From Africa, Saldanta Bay and Kuria Muria Islands. 



Bat Guano, the product from the floors of caverns inhabited by 

 bats, have sometimes been sent to market as a rich fertilizer. It is 

 found notably in Cuba (W. I.) and in N. Borneo. It possesses a char- 

 acteristic dark brown colour and exhibits the undigested parts of 

 beetles wings and insect debris. 



BONE BEDS. 



These are found in nearly all sedimentary strata, from the Devo- 

 nian up to the present time, but with the appearance of those remark- 

 able reptilia in the Permian age, we find that these kinds of phosphatic 

 provisions of nature took enormous developments, augmenting the 

 resources previously furnished by the amphibia of the Carboniferous 

 epoch. 



