834 THE CANADIAN NATURALIST. [Vol. X. 



England afford striking examples of this kind. We have com- 

 mon mica, in sheets a yard across ; feldspar has been observed 

 where a single cleavage plane measured ten feet ; gigantic hexag- 

 onal prisms of beryl, four feet long and more than two feet in diam- 

 eter, and weighing over two tons, have been described ;'spodu- 

 mene crystals six to seven feet iu length and a foot or more 

 across, and masses of rock crystal of immense size have been 

 found. Canada and New York have given crystals of apatite, 

 phlogopite and sphene which for these species are of marvellous 

 grandeur in dimensions. Many other x\merican localities might be 

 mentioned where giant crystals occur. While it is true that these 

 are extraordinary instances it is also true as a general fact common 

 to a very large proportion of the minerals found in this country 

 that the species occur in much larger crystals than those obtained 

 from European localities. Another point worthy of note is the 

 occurrence in comparatively large quantities, and over wide areas, 

 of some of the rarer elements as constituents of the minerals 

 found. In illustration of this we have, among the rare earths, 

 glucina combined with silica and alumina in the mineral beryl, 

 occurring in large quantity, and perhaps in a hundred or more 

 places; zirconix^ia the mineral zircon, is also very widespread in 

 its ranire of occurrence as an original constituent of the older 

 rocks, as well as a vein mineral ; localities are known which have 

 furnished this rare species by the hundredweight. The cerium 

 earths are found largely in the mineral allanite, which occurs in 

 so many places that it may be said to be a common mineral in 

 the United States. These earths are also found in the rare 

 phosphate monazite, a mineral that in America has a wide 

 range of localities, and recently this species has been found iu 

 crystals of two, three, and in one instance, of eight pounds in 

 weight. Again, three new earth metals, mosandriim, phiUip- 

 ium and dccipium have been described as occurring with the 

 cerium earths and yttria in the North Carolina samarskite. The 

 rare alkali metal Hthiiun, sometimes associated with the still rarer 

 metals ruhidium and caesium, is found not only of wide-spread 

 occurence in our lithia micas, but the mineral spodumene, contain- 

 ing from five to eight per cent, of lithia, occurs by the ton in at 

 least one locality and must be looked upon as one of the common 

 American minerals, being found in the granite veins in Maine, 

 New Hampshire, Massachusetts and Connecticut, and as far 

 south as North Carolina and Georgia. Lithia is al=o one of the 



