284 The American Geologist. May, 1892 
hopper was filled with a mixture of broken ice and red sandstone, 
about half and half in bulk. The sandstone gave the mixture ¢ 
dark color, and also gave it a specific gravity much greater than 
that of the pure ice in the valley. The lever was then operated, 
and the hopper kept supplied with the mixture until it was forced 
up through the clear ice in the valley, as shown by the dark mass 
between FF in the cut. A freezing mixture was then applied to 
the sides of the box, and the whole covered with canvass and 
allowed to remain until frozen, when one side was removed and a 
photograph taken from which the cut was made. Three similar 
experiments had been made previously, with gravel and cement, 
all resulting the same. 
The colored material introduced at the bottom of the upper 
end of the valley appeared at the surface of the ice with rounded 
front, ‘‘in true glacial style.” 
PRELIMINARY DESCRIPTIONS OF NEW BRACHIO- 
PODA FROM THE FRENTON AND HUDSON 
RIVER GROUPS OF MINNESOTA.* 
N. HW. Wincnetn and Cuarites Scuucwert, Minneapolis. 
Lingula riciniformis var. galenensis. 
The conspicuous difference between LZ. réciniformis Hall, and 
this variety, is that the former is constantly two thirds the size of 
the latter, and that the greatest width is across the center of the 
length of the valves, while the variety is widest in the anterior 
third, In the Galena horizon at Oshkosh, Wis., this variety is 
not rare, and there attains twice the size of LZ. réctuiformis Hall. 
Plate xxix, figs. 10, 11. 
Formation and locality. Galena shales, north branch of the Zambro 
ELVieCE, 
Lingula (Glossina) deflecta. 
Shell medium size, subtriangular; lateral margins diverging 
more or less rapidly from an acute apex, to the broadly rounded 
and deflected anterior third. Shell substance thick, and marked 
by strong, irregular concentric lines of growth, between which are 
*The designations of figures and plates refer to Vol. 1II of the Final 
teport on the Geology and Natural History of Minnesota. Advance 
prints distributed Apr. 1, 1892. 
