INSTITUTE OF SCIENCE, PHILADELPHIA. 53 



between the date of the publication of Conrad's paper and 1 880 is the 

 report of personal observations made in the northern half of the State by 

 Dr. Eugene A. Smith, State Geologist of Alabama, published in the 

 American Journal of Science for 1881. This assiduous investigator 

 collected largely in the way of rocks and fossils, and at localities 

 sufficiently removed from one another as to permit of a broad insight 

 into the geology of the region. From his observations it appeared that 

 at least a considerable part of the northern half of the State, instead of 

 representing a recent formation, as was supposed by many, was in reality 

 underlaid by heavy beds of fairly ancient limestone, which in the 

 characters of their organic remains recalled the upper white lime- 

 stone of Alabama. The fossils, which were kindly placed in my hands 

 for determination, proved the correctness of the inference as to their age. 

 I identified among them two or more species of Foraminifera, one a 

 large orbitoide, of very nearly the dimensions of the Orbitoides Mantclli, 

 representing it, and undeniably the analogue of the European Orbitoides 

 cpldppinin, and an Operculina, very nearly related to, if not identical 

 with, the 0. cotuplanata. Some of the rock specimens submitted to me 

 were made up of practically nothing but the tests of the aforesaid orbi- 

 toide, and of a smaller species more of the type of 0. Forlisii (disfansa). 

 From the examination of these specimens I had no hesitation in referring 

 the rocks holding them to the Oligocene formation. The localities noted 

 by Dr. Smith for the occurrence of this formation are located in the tract 

 included between Jackson Co. on the west, and Marion Co. on the south, 

 and it was correctly conjectured that over much, or most, of the intermediate 

 region where no observations had as yet been made, or where there were 

 no outcrops, the same rock would be found as the underlying structure. 

 From one locality, Rock Spring, Orange Co., Dr. Smith obtained rock 

 specimens which differed very essentially in both litljological and faunal 

 features from the specimens obtained at the other localities, indicating 

 the existence of a distinct formation. Among the fossils I identified a 

 number clearly indicative of the Miocene age of the formations such as 

 Pcctcn MeuUsomus, Cardita arata, C. granulata, Venus alvcata, etc., fixing 

 the most southerly extension of the Medial Tertiary formations of the 

 Atlantic slope. This patch of Miocene is not improbably continuous 

 with the Miocene area of southern Georgia. 



The reference of the greater part of the northern half of the State to 

 the Oligocene formation has been more than justified in the light of 

 subsequent investigation, which has disclosed the existence of the older 

 Tertiary rock in many new localities on the Wacasassa, at Archer, 

 Arredonda, on the Homosassa, Cheeshowiska, etc. From the Cheesho- 

 wiska, some four miles from its mouth, Mr. Joseph Willcox, in 1882, 

 obtained large masses of rock, densely charged with foraminiferal remains, 





