INSTITUTE OF SCIENCE, PHILADELPHIA. 125 



Acad. Nat. Sciences Phila., July, 1882; Contributions to the Tertiary 

 Geology and Paleontology of the United States, 1884, p. 80) I call atten- 

 tion to the vague description and apparently imperfectly represented 

 figure of the fossil which Conrad refers to Nummulites, remarking that 

 its reference appeared to me very doubtful. Up to that time I had not 

 seen any specimens of the fossil in question, my search among rock 

 fragments that had been sent to me by different parties from Florida 

 proving in all cases ineffectual. At Ballast Point, on Hillsboro Bay, and 

 again in the rock at Magbey's Spring, about a quarter of a mile above 

 the town of Tampa, on Hillsboro River, I was fortunate in finding great 

 quantities of the form that I had been so long in search of, and which 

 had been overlooked for a period of nearly forty years. A cursory 

 examination of the species immediately confirmed my suspicions as to 

 the inaccuracy of its generic determination. The species does not even 

 belong to the great group which includes Nummulites, much less to the 

 genus ; it is a true orbitolite, and very close specifically to if not, indeed, 

 identical with the common European Orbitolites complanata. Its internal 

 structure can be determined even with an ordinary hand-magnifier with 

 considerable precision. The greater number of the individuals are 

 regularly involute, but others assume the cycloidal form represented by 

 Conrad, an appearance in some cases brought about by an irregular 

 exposure of the different planes of the test. More frequently, perhaps, 

 the same form is due to an actual exocyclic involution of the test, as has 

 also been observed by Carpenter and others in the European fossil and 

 the recent species. 



The probable Miocene age of the Orbitolitic rock has been commented 

 on in the last section. 



Other Foraminifera observed in the peninsula were : 



Nummulites Willooxi, Heilpr. 



Proc. Acad. Nat. Sciences Phila., 1882, p. 191 ; Contributions to the Tertiary Geol- 

 ogy and Paleontology of the United States, 1884, p. 80. 



Very abundant in the rock at Loenecker's, on the right bank of the 

 Cheeshowiska River, about four miles above its mouth. 



Nummulites Floridensis, Heilpr. 



Proc. Acad. Nat. Sciences Phila., 1884, p. 321. 



Associated with the preceding in the same locality. 



Orbitoides ephippium (sella), Schloth. 

 Die Petrefact., 1820, p. 89. 



Very abundant at the nummulite locality on the Cheeshowiska; less 

 abundant near the mouth of the river (John's Island, etc.), at the spring- 

 head, and in the rock of the Homosassa. 



