J. P. Kimball—Grahamite in the Huasteca, Mexico. 281 
#8¢ of the sandstone series—requires the support of other facts. 
rock surfaces are absolutely unbroken, while covered with a 
ry forest ; hence the present impracticability of a success- 
Search for fossils in this part of Mexico. nA 
Burkhart also identified in the banks of the “Rio Grande 
(Amajaque) the same formation of clay shale observed by him 
igq¢'tfeuthalt und Reisen in Mexico in den Jahren 1825 bis 1834. Stuttgart, 
"1, p. 53. 
1827, ta Geognostica de los principales Distritos Minerales del Estado de Mexico, 
