Geology and Mineralogy. 459 



upon soil erosion. The paper is of timely interest, first, because 

 of the new law providing for the creation of the Appalachian 

 forest reserves, and, second, because it has recently been suspected 

 in some quarters that the earlier pictures of soil destruction were 

 overdrawn. The author finds about 74 per cent of the total area 

 still forested. Even this amount, however, is considered too 

 small. Under the given conditions of slope gradient, soil tex- 

 ture, rainfall, etc., it is considered unsafe to have more than 18 

 per cent to 20 per cent of the surface cleared. Clear-cut illustra- 

 tions of soil erosion are supplied in a variety of situations : (l) 

 on sodded " balds " where over-grazing and trampling by cattle 

 have broken the turf and started landslides that quickly develop 

 into gullies ; (2) on all slopes where lumbering has removed the 

 original protective covering and hastened the action of rain-wash; 

 (3) on cleared and abandoned slopes once used for agriculture. 

 In the last-named case the harm has been underestimated in the 

 past. Undercutting and caving, once started in a cleared area, 

 often extend upward into forested tracts, and the debris derived 

 in this manner is washed downward into the forest below. Some 

 porous soils were found to be erosion-resisting but their aggre- 

 gate area is not relatively great. The allowable limit of steep- 

 ness for cleared lands, 15°, is almost every where exceeded, and in 

 many places greatly exceeded. Terracing is practised on a 

 wholly inadequate scale. There is increased silting on the flood 

 plains and in the stream channels, a conclusion applied to all 

 streams draining catchment areas that have been extensively 

 cleared. One gains from the paper a clear and powerful impres- 

 sion of destructive erosion on exposed mountain soils and of 

 destructive sedimentation on the flood plains. It is with a feel- 

 ing of great satisfaction that one contemplates the beneficent 

 results that may flow from the recent action of Congress after so 

 conclusive an argument against the further unguarded use of the 

 soil. I. B. 



2. Preliminary Notes on the " Chazy " Formation in the 

 Vicinity of Ottawa ; by Percy E. Raymond. The Ottawa 

 Naturalist, xxiv, Feb. 1911, pp. 189-197. — The following sum- 

 mary is given : " The sections in the vicinity of Ottawa show 

 about 250 feet of strata between the Beekmantown and the base 

 of the Black River. These strata are characterized by two 

 groups of species. The lower 125 to 135 feet contain a small 

 fauna, some of whose species are found in the upper part of the 

 Chazy formation of the Champlain Valley, and this portion is 

 undoubtedly to be correlated with the Upper Chazy . . . 



"The upper portion of the section consists of i 15 to 125 feet 

 of limestone, sandstone and shale, with fossils more nearly akin 

 to those found in the Black River and lacking the typical Chazy 

 species. . . . This portion of the section ... is capable of sub- 

 division into two members, the lower of which contains most of 

 the shale and sandstone, and the upper the pure limestone. The 

 lower portion contains an immense number of small ostracods, 



