1896.] MICROSCOPICAL JOURNAL. 235 



blocks and when dry is quite indurated, but it yields to 

 the trituration treatment, f^iving the discoidal diatoms 

 as clear and as transparent as glass, with the specific 

 reticulation quite distinct. At another point two miles 

 north of Enterprise at the Okatibhee Creek iron railroad 

 bridge in the south bank of the creek, and in its bed 

 samples of a clay that falls to peices on wetting yielded 

 an abundance of radiolarian forms comprised under a 

 few genera and species having their spines intact. These 

 forms might be removed pure by millions by a simple 

 washing process, the clay being of that texture as not to 

 require trituration for reduction of the aluminous matrix. 

 The diatoms in this deposit were not abundant but were 

 associated in small numl)ers with the other organ- 

 isms. 



But at another point at the base of the bridge pier an 

 outcrop of sandy stratified clay reduced very easily in 

 water gave a characteristic showing of marine discoidal 

 diatoms with few radiolarians 



In addition to the diatomaceoiis and radiolarian beds, 

 there were deposits of calcareous marls at many points 

 in the vicinage of Enterprise, which deposits are usually 

 void of any silicious micro-organisms but furnish green- 

 sand casts of interest in their peculiar structure, and 

 also of foraminiferal shells. The mtirl deposits are 

 rather coarse in texture and on their weathered surfaces 

 thousands of discoidal echinoderms are scattered which 

 show microscopic ornamentation on their white sur- 

 faces. 



In a previous article in the Journal in relation to the 

 radiolarian deposits of Ala. and Miss., I alluded to an 

 extensive iormation a few miles north of Enter2)rise, as 

 being a typical illustration of the Radiolarian formation 

 (Buhrstone; Eocene). During the month of May, of this 

 year, I was enabled to examine this point, which is 

 locally known as "White Bluff" or the flag station known 



