L30 proceedings of o'ttawa meeting. 



small quantity, the impression conveyed being thai the sand cannot in any large 

 part be considered as directly derived from crystalline rocks, tn the coarsesl speci- 

 mens of sand resulting from the mechanical analysis of the bow Ider-clay the con- 

 stituent grains were easily separable by the unaided eye. ami among them were 

 found small fragments of shells and a number of foraminifera. Of these a small 

 collection was picked out and mounted, comprising about two dozen individuals, 

 and representing perhaps halt' the number present in about an ounce of the material. 



These have been examined by Mr J. F. Whiteaves, who reports all the speci- 

 mens but three to be referable to PolystomeUa strkttopunctata, Frichtel and Moll, 

 w hile of the remaining specimens one is PulvLnulina karsteni, Reuss, another prob- 

 ably Nodosaria (Olandulina) laevigata, D'Orb., and the third not determinable, being 

 encrusted and badly worn. 



The Polystomellse are rather small and depauperated in appearance, resembling 

 in this respect those found in the upper part of the gulf of Saint Lawrence/- where 

 the water becomes distinctly less saline than normal, but the collection so far ex- 

 amined is quite too small to warrant any theorizing on this fact. 



In examining the medium grades of sandy material under the microscope numer- 

 ous fragments of sponge spicules were noticed. These weir generally straight, sim- 

 ple and tubular, but, so far as observed, never perfect. No diatomacse were seen, 

 though more extended and minute search might probably lead to this discovery. 



In containing broken shells and other forms of marine life, the bowlder-clay 

 here described resembles that of some parts of the Queen Charlotte islands already 

 described by the writer, f The available evidence is, however, insufficient to en- 

 able us to refer the deposit of bow lder-clay of which Middleton island is composed 

 to its proper place in the sequence of events of the glacial period, for elsewhere on the 

 coast, and probably generally, there are two distinct bowlder-clays, which can only 

 he separated with certainty when both are seen. This bowlder-clay may have 

 been formed as a marine bank in proximity to the fronts of great glaciers debouch- 

 ing along the coast of the mainland to the northward, upon which detached ice- 

 bergs grounded from time to time. 



The interstratilied layer or layers of pebbly material observed by Mr Macoun 

 might thus be explained, and it appears further to be borne out by the description 

 by Mr Dall, whose attention seems to have been more particularly directed to 

 evidences of bedding, and who writes: 



"The island is composed of nearly horizontal layers of soft clayey rock, containing many peb- 

 bles and even bowlders of syenite and quartzite, some rounded and others of angular shape. 

 Above the claystone is a layer of gray sand covered with several feel of mould and turf."J 



It is perhaps, however, on the whole more probable that this projecting mass of 

 bowlder-clay forming Middleton island represents a portion of a morainic accumu- 

 lation formed at or near the seaward edge of an ice-field derived from the adjacent 

 njainland, and which pushed southward or in a direction at right angles to that 

 of the average trend of the nearest continental coast. 



The broken character of the shells seems to favor the belied" that the material 

 was ploughed up from the sea bottom and -really disturbed, rather than to show- 

 that it represents merely a bank upon which glacial debris was occasionally dis- 

 charged. Such a bank might probably be from time to time poached up by 



*See I anadian Naturalist, L870. \>. itj. 



: Quart. Jour. Geol. So :., M ly, 1831. K iporl of Progress, G sol, Surv: of Canada, l878-'79, p. 91 B, 

 »p. supra '-it., p. 260, 



