J. W. DAWSON ON THE PHOSPHATES OP CANADA. 287 



through the matrix there are also small fragments, invisible to the 

 naked eye, of brown and blue phosphatic matter. 



One of the nodules from Alumette gave to Dr. Hunt 36-38 of 

 calcic phosphate ; one from Hawkesbury 44*70 ; another from 

 Riviere Ouelle 40-34; and a tube from the same place 67*53*. A 

 specimen from Kamouraska, analyzed by Dr. Harrington, gave 

 55-65 per cent. One of the richest pieces of the linguliferous sand- 

 stone from St. John yielded to the same chemist 30-82 of calcic phos- 

 phate and 32-44 of insoluble siliceous sand, the remainder being 

 chiefly carbonate of lime. 



Various opinions may be entertained as to the origin of these phos- 

 phatic bodies ; but the weight of evidence inclines to the view origin- 

 ally put forward by Dr. Huntf, that the nodules are coprolitic ; and 

 I would extend this conclusion with some little modification to the 

 tubes as well. The forms, both of the tubes and nodules, and the 

 nature of the matrix, seem to exclude the idea that they are simply 

 concretionary, though they may in some cases have been modified 

 by concretionary action. There are in the same beds little piles of 

 worm-castings of much smaller diameter than the tubes, and less 

 phosphatic ; and there are also Scolilhas-like burrows penetrating 

 some of the limestones, and lined with thin coatings of phosphatio 

 matter similar to that of the tubes. Further, the association of 

 similar nodules in the Chazy limestone with comminuted Lingular, 

 as already stated, is a strongly confirmatory fact. 



The tubes are of unusual form when regarded as coprolitic ; but 

 they may have been moulded on the sides of the burrows of marine 

 worms ; or these creatures may have constructed their tubes of this 

 material, either consisting of their own excreta or of that of other 

 animals lying on the sea-bottom. In any case, the food of the 

 animals producing such excreta must have been very rich in solid 

 phosphates, and these animals must have abounded on the sea- 

 bottoms on which the remains have accumulated. It is also 

 evident that such phosphatic dejections might either retain their 

 original forms, or be aggregated into nodular masses, or shaped 

 into tubes or burrows of Annelids, or, if accumulated in mass, 

 might form more or less continuous beds. 



The food of the animals producing such coprolites can scarcely 

 have been vegetable ; for though marine plants collect and contain 

 phosphates, the quantity in these is very minute, and usually not 

 more than that required by the animals feeding on them. 



We must therefore look to the animal kingdom for such highly 

 phosphatic food. Here we find that a large proportion of the 

 animals inhabiting the primordial seas employed calcic phosphate in 

 the construction of their hard parts. Dr. Hunt has shown that the 

 shells of Lingida and some of its allies are composed of calcic 

 phosphate ; and he has found the same to be the case with certain 

 Pteropods, as Conularia, and with the supposed w r orm-tubes called 

 Serpulites, which, however, are very different in structure from the 

 tubes above referred to. 



* Geology of Canada, p. 461. t Ibid. 



