208 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 24, 



porous and moderately fine-grained and yield good fire-stones, while 

 others are coarse, and, in addition to quartz-pebbles, hold a multi- 

 tude of phosphatic nodules, mingled with small fragments of what 

 appear to be Lingulce. At Grenville, where these beds have been 

 most exposed by the cutting of the canal, they are found to cross 

 the Ottawa to Hamiltonville in Hawkesbury, and to extend half a 

 mile back from the river ; and half a mile beyond them a low escarp- 

 ment presents the base of the Chazy Limestone, composed, as in the 

 St. Ann's section, almost entirely of Atrypa plena. In this rock 

 also small phosphatic nodules exist in some abundance, a few of 

 which hold small fragments of shells. 



Phosphatic nodules have also been met with higher up on the 

 Ottawa, at the Allumettes Rapids, in a conglomerate bed occupying 

 the same stratigraphical position as the Grenville beds, but there rest- 

 ing on the gneiss. Great numbers of one large species of Lingula, 

 very like L. parallela of Phillips, and a few of Pleurotomaria or 

 Holopea, occur with the nodules. Every one of the Lingulce is im- 

 bedded in a coating of the phosphate, and in one instance a fragment 

 of a Lingula was found lying across the length of the nodule. The 

 specimen of Pleurotomaria is a phosphatic cast of the interior of the 

 shell. 



I may here mention also, that much higher in the Lower Silurian 

 series of strata, in fact, just above the Hudson River Group, but con- 

 siderably removed from this locality, phosphatic nodules occur in 

 great abundance, and one of them, obtained at Riviere Ouelle, on the 

 south side of the St. Lawrence, seventy-five miles below Quebec, 

 whence the limestones and sandstones in which they occur are trace- 

 able to Point Levi, opposite the Capital, so much resembles a frag- 

 ment of a cylindrical bone, and is so like bone in chemical compo- 

 sition, that I have had it sliced, fully expecting it would show bony 

 structure. This, however, is wanting ; but the specimen suggests the 

 inquiry, whether, confined in its stony mould, any chemical action 

 may have been exerted to obliterate its original structure without de- 

 stroying its form. 



I append to this paper the analyses, with which my friend Mr. Hunt, 

 the chemist attached to the Canadian Survey, has furnished me, of 

 four phosphatic specimens, two of them from the Riviere Ouelle, one 

 of these being the bone-like fragment ; the third is from the Chazy 

 beds of Hawkesbury, and the fourth, from the Allumettes Rapids. 

 By these analyses it will be perceived that the specimens yield from 

 36 to Q7 per cent, of phosphate of lime, and that they all, on being 

 heated, give out ammonia and an animal odour like that of burnt 

 horn. One of the Grenville nodules was tested for phosphate of 

 lime, and found to contain it largely, and it also gave out the animal 

 odour, but it was not quantitatively analysed. 



