910 The American Naturalist. [November, 
“ The overlying deposits are generally a foot or two of mud, 
_ the same thickness of clay, a layer of peat sometimes interven- 
ing, and below the clay shell-marl containing everywhere the 
relics of fresh-water testacea of existing species; some of them 
perfect, others decomposing. Sir Chas. Lyell, in his geologi- 
cal tour through the State of New York, found at Genessee, the 
bones of the mastodon in a bed of shell-marl below the peat, 
corresponding, he remarks, with the situation of the fossil elks . 
of Ireland, generally considered to have been buried in bog- 
mud or peat’ swamps, but which, in fact, lie in a stratum of 
shell-marl.” 
It seems probable that the enormous quantities of moa bones 
found in the turbary area at Glenmark, New Zealand, afford 
some grounds for questioning the destructive influence of vege- 
table acids. According to Dr. Von Haast, a large swampy 
tract in Glenmark, covering a depressed region and partaking 
of the mingled characters of an estuarine and lacustrine basin, 
contains an incredible number of the skeletons of these great 
birds. The bones occur here in separated patches or nests, 
and the impression, made by their distribution, is that of a 
sudden flight of groups of the birds over this marshy delta 
which has sunk in places beneath them, and thus entrapped 
them in constantly increasing numbers. Bones of twenty or 
thirty individuals, of all sizes and ages, and lying closely 
packed in spots about five or six feet in diameter, are found 
with no bones near them, as if, at particular points, the birds 
had disappeared, one after another, in the enveloping mass of 
vegetable débris and soft mud. Evidences here are everwhere 
plentiful of successive freshets by which accumulations of 
trees, seeds, stems and drift timber have been formed, which, 
with the growth of bog plants, created a deep vegetable blanket 
in which the moa bones are immersed. Four to seven feet of 
pure black peat are succeeded by two to three feet of more im- 
pure peat, in which the bird bones are more commonly laid, 
and under these a hard clay bottom completes the section. It 
8 Geology of Canterbury and Westland, New Zealand, J. Von Haast. See also 
Ann. & Mag. Nat. Hist., Aug., 1844, Rev. W. Colenso; Transac. New Zealand 
Inst., Vols. IV, VI, J. Von Haast. 
