332 THE AMERICAN MONTHLY [Nov. 



species, and the breaking off of the spines of such species 

 as may chance to have them. 



I conld find no process of acid treatment that would 

 remove the amorphous clay particles which are an imped- 

 iment to the concentration of the Eadiolarian bodies. 

 When a relatively large amount of the clay has been 

 cleaned by the reduction process noted above, it then be- 

 comes possible by various .expedients to get sei)arately 

 the spherical Radiolarians, and the Foraminifera. But 

 the discoidal diatoms and ilatish sponge spicules usually 

 remain together. The very fine sand and mica scales are 

 finally eliminated from the desired fossils, as they gener- 

 ally adhere to any Ja23anned surface, and may be blown 

 away as of no use. The Alabama and Mississippi Eadio- 

 larian deposits owe their refractory nature largely to a 

 metamorphosed condition characteristic of the Buhrstone 

 horizon of the Tertiary deposits the world over. By 

 silicious infiltration, sedimentary strata, of a partially cal- 

 careous origin and containing spiral shells and minute 

 foraminifera, have been silicified, as is clearly shown by 

 the foraminifera, and the clay material itself resisting so- 

 lution in the strongest of known acids. 



The Eadiolarian stone from Jeremie, Haj'ti, dissolves 

 speedily in cold citric acid, which dissolves likewise the 

 profusion of calcareous foraminifera, leaving intact the 

 Eadiolarians and sponge spicules, while the same nat- 

 ural rock has a flinty toughness. The well known Bar- 

 badoes chalk is soft and tender enough to be reduced and 

 cleaned by boiling solutions of soda or potash. Both of 

 the last-named deposits are strikingly different in the 

 character of the fossils held therein. By comparison, the 

 paucity of species as noted in the Alabama and Miss- 

 issippi deposits will be seen. There still remains a 

 probability that at some future time strata or thin layers 

 may be found among those in Alabama and Mississij^pi 

 of the same general character and richness, as noted 



