G. GENERAL NATURAL HISTORY AND ZOOLOGY. 341 



iraens of all but twenty-three. The catalogue appears in 

 small folio, about the size of an English Blue-Book, and is 

 provided with ample margin for manuscript notes. The 

 total number of species to be enumerated by them is 3565 ; 

 and allowing 435 for those not occurring south of the United 

 States and for undescribed species, we will have 4000 as an 

 approximate estimate of the bird fauna of the New World. 



ETHNOLOGY OF THE PEAT BOGS. 



At a recent Congress of Prehistoric Anthropology held at 

 Brussels Mr. Steenstrup made a communication upon the peat 

 bogs of Denmark, in which he remarked that these have been 

 divided into three classes, according to the plants which have 

 principally contributed to form the different layers namely, 

 the Skovmoser, or forests; the Kjaesmoser, or prairie bogs; 

 and the Lyngmoser, or the bogs composed of moss or heath. 



The Skovmoser are those which are of most interest, since 

 we can find in them layers superimposed one upon another, 

 which can even permit ns to determine the epoch of the 

 animals which have perished in the peaty mud. The lay- 

 ers found near the exterior are usually in the best condition, 

 as they are usually in their natural position, having escaped 

 the changes that have acted upon the centre. Here we find 

 the remains most characteristic of the forest in the following 

 order : first, the aspen {Populus tremula) ; second, the pine 

 {Plnus sylvestris) ; third, the oak (Quercus sessiliflora) ; fourth, 

 the alder {Alnus gliitlnosa) ; fifth, the beech (Fagus sylvatica). 

 This last grows to-day throughout Denmark. 



These facts have, of course, long been known ; but quite 

 lately Nathorst has found that beneath the layers already 

 mentioned occurs an arctic flora, composed of JBetula nana, 

 Dry as octopetala, Salix herhacea, eic. These latter deposits 

 are not of fluvial origin, but have been formed by water filter- 

 ing across the walls of the basin, and are all of a local vegeta- 

 tion ; so that we have a local series of layers marking all the 

 modifications of the Danish climate. The arctic flora corre- 

 sponds to that of the southern boundary of Lapland, or that 

 of the sea-level of Denmark. At present flint implements 

 have only been collected in the layers of the Plnus sylvestris; 

 but Mr. Steenstrup has found them in layers of the arctic flora. 

 He has found bones of the reindeer several times, but only in 



