116 TRANSACTIONS OF THE [FeB. 23 



A chemical analysis of tlie nodules from Div. 16^ gives the 

 following results : 



SiO. 24.74 



Alzba ----- 11.85 



FesOa 11.44 



CaO . - - . - 22 35 



Mg O 2.29 



K,0 0.59 



Na,0 1.41 



P,05 14.99 



CO. 3.53 



-j^^gg] atllO° - . - - 3.43 



j below red heat . . - 3.44 



lOO.OG 



This shows an unusually large percentage of iron and alumina, 

 and a low one of phosphoric acid. Much of the silica seems to 

 be in the form of quartz or of silicates insoluble in acids. 



Other Phosphate Nodules in the St. John Group. — The only 

 other occurrence of phosphatic nodules in the St. John Group 

 is in Div. 2c, at the City of Saint John, where beds containing 

 an abundance of Linguloid shells bear also irregularly rounded 

 or flattened nodules of small size, which are composed of com- 

 minuted Lingulee, and have been considered to be coprolites. 

 The occurrence, shape, and composition of these are quite 

 different from the Hanford Brook material ; they are black and 

 shining, showing the little polished surfaces of the comminuted 

 shells. They are not accompanied by glauconite sand. 



Comparison With Other Phosphate Deposits. — Phosphate beds 

 are well known in many other parts of the world. Those of the 

 Cambrian and Lower Silurian of Wales, where one naturally 

 looks for the nearest analogy to those of the Sf. John Group, 

 have been described by Mr. Davies'-^^, and their origin is discussed 

 by Dr. Hicksf in an article on Phosphates in the Cambrian 

 Rocks. They seem to be much more altered than those at 

 Hanford Brook, but of much the same general character. They 

 contain, however, a large amount of carbonaceous matter, and 

 no mention is made of any glauconite accompanying them. 



* Quart. Jour. Gol. Soc, London, Vol. XXXI ■, p. 357. 

 t Op. cit., p. 368. 



