412 The American Geologist. June, isos 
raine shale of the Hudson group, 640; Utica shale, 233; Trenton, 637-|-; 
Calclferous, 320 (?); and Potsdam, 410 (?). This general section is com- 
pared with two others measured by Mr. Prosser farther west in New 
York, respectively following the valleys of Cayuga lake and of the 
Genesee river, and with one section determined in eastern New York by 
C. A. Ashburner, from the top of the Catskill mountains to the bottom 
of the Mohawk valley. 
A neio Tamiopteroid Fern audits Allies. By David White. Bulletin, 
G.S.A., vol. iv, pp. 119-132, with a plate and diagram indicating hy- 
pothetical relations: Feb. 23, 1893. The fern here described, Tcniiopteris 
missouriensi-s, is represented by eleven specimens collected in the Lower 
Coal Meas^ures 8 to 9 miles south and southeast of Clinton, Mo. The 
species is of peculiar interest from certain features showing close rela- 
tionship to the genus Alethoptei'is. 
Some Elements of Land Sculpture. By Lewis Ezra Hicks. Bulletin, 
G. S. A., vol. iv, pp. 133-146, with twelve figures of erosion outlines; 
Feb. 2o, 1893. The processes of subaerial land erosion by weathering 
and by the washing of rains, rills, and larger streams are instructively 
discussed, with illustrations chiefly taken from the area of the great 
plains and bad lands in the region drained by the Missouri river. 
Some Dynamic and Metasomaticphe7iomena in a metamorphic conglom- 
erate in the Oreen m,ountains. By Chakles Livy Whittle. Bulletin, 
G. S. A., vol. iv, pp. 147-166, with a plate showing secondary enlargement 
of clastic tourmaline, and five figures in the text; Feb. 25, 1893. The 
formation studied is a Lower Cambrian conglomerate, in large part 
changed to ottrelite schist, which phase attains a thickness of several 
hundred feet and is traced several miles across the anticlinal axis of the 
Green mountain range, from Mendon eastward to North Sherburne, in 
the northeast part of Rutland county, Vermont. The latest change that 
this schist has undergone is the incipient alteration of its ottrelite into 
chlorite. In Chittenden, the next township on the north in the same 
county, the stratigraphic continuation of the ottrelite schist is a well- 
marked conglomerate, in which quartz pebbles and small boulders, up 
to 18 inches in length, make nearly 90 per cent, of the detrital material. 
Gneiss and feldspar pebbles are also common, the latter being occasion- 
ally two to three inches long. The groundmass consists of granular 
quartz, magnetite, plates of muscovite, and prisms of sericlte. In this 
rock small fragments of tourmaline crystals, often water-rounded, have 
been filled out by the deposition of secondary tourmaline perfectly 
oriented with the core, in the same way as the enlargements of quartz 
grains which have been described by Irving and Van Hise. In one of 
the examples figured the secondary growth is bounded by nearly complete 
crystallographic faces. 
Notes on a little known region in northwestern Montana. By G. E. 
Culver. Trans., Wisconsin Academy of Science, Arts, and Letters, vol. 
viii, pp. 187-205, with map; Dec. 30, 1891. Besides many valuable ob- 
servations on the topographic features and stratigraphic geology of the 
