234 THE AMERICAN MONTHLY [July 



a considerable area of the tertiary sedimentary forma- 

 tions, all of which are of special interest to students of 

 micro-geology or to the general microscopist. There is 

 a strip of territory occupying fully one-third of the 

 Southern })ortion of the states of Alahama and Mississi})pi 

 and extending to the shores of the (lulf of Mexico, which 

 is now known to furnish inexhaustible fields of strata 

 made up in greater or less degrees of richness of micro- 

 zoan remains. There are foraminifera, radiolarians, 

 sponge sfdcules; diatoms of marine origin, si)ines and 

 tests of micro-echinodermata, corallines and lignitic 

 strata containing the resinous spores characteristic of the 

 fern vegetation. There are also mineral grain inclusions 

 of various kinds, the result of the decomposition of the 

 archaic or primary formations as silex, mica, alumina, 

 tourmaline, zircon, magnetite, greensand, i)yrite, selenite 

 and fossil resinous granules, phosphatized bones 

 of various extinct fossil vertebrates, sharks' teeth of minute 

 size, etc. 



While investigating the formations for a few days at 

 Enterprise, Miss., I very promptly determined three 

 characteristic stratified deposits of microscopic interest; 

 the first being at the level of the water in the Chickasaw- 

 hay River, ata point a little south ofauew steam saw mill 

 in process of erection and which will remain a permanent 

 land mark from which to locate the deposit. At this 

 point a particularly tough and close grained bluish clay 

 shelves into the water abruptly. This material when 

 tested right on the spot by the trituration method, show- 

 ed that it was a deposit of marine fossil diatoms corres- 

 ponding to the recent existing species found in the clays 

 of the bays bordering the Gulf. There were large and 

 small species of coscinodiscus, actinoptychus, actinocy- 

 clus, melosira and triceratium with a sprinkling of 

 radiolarian forms. This clay breaks up into cubical 



