Schoolcraft’s Localities. 47 
ted gypsum. This mass is about 9 inches in diameter, and 
the cnaenn merely forms a crust around the aggregated 
mass of crystals. 
alcareous Spar.—Roche de Bout, on the Maumee ri- 
ver, Wood County, Ohio. Imbedded in limestone, and 
exhibiting its most common forms of crystalization. Fre- 
quently in perfect dodecaedrons of a light yellow hue, Al- 
59 massive and translucent. of a honey yellow colour, for- 
sing a ae. te bend of the ri wi so esta oub his right, a le- 
el prairie with a small Indian village upon its margin, 
ope echieslghaeiaiapdiaamtaneion ns cao tees of 
Love desiabciemaecioeeeaer ieee with forest a 
small and recent growth. These cliffs are a cale: 
more or less spongy or vesicular in their structure, and im- 
bed, plentifully, fragments of shells, stems of vegetables, 
leaves, and other remains. The external surface is some- 
what blackened, by the weather, wo the fresh fracture dis- 
closes a light grey, yellowish grey, or greyish white colour. 
This is probably the newest rock formation between the 
Ohio and the Mississippi rivers! How ciateiins it is, can- 
ps ne stated. It disappears, or is hid below alluvial soil, as 
the mouth of the Tippecanoe 
a) us Gypsum.—N eekimenis,* or Genie Island, lake 
Horo, Michigan Territory. This small island is situated 
e miles distant from Michilimackinac, on the route to 
Pe “Sault of St. Mary. The gypsum is imbedded in a kind 
of loamy clay, which forms a pretty’ extensive: flat, upon 
ihe south-eastern end of the island, which has so little ele+ 
vation above the water, that it is partially inundated during 
the prevalence of certain winds. The masses are detach- 
ed. Sometimes the fibres are 4 or iebonds long, and pos- 
sess a pearly white Where e to the air, 
are somewhat decayed, and broken down. This gypsum 
is associated with a gray a variety, imbedding small 
#T he nam, eee ee) ee 1 
to if. 
—- = ¢ 
