FAUNA OF OETHAULAX PUGNAX ZONE. 11 



The Ocala limestone is described as light gray to white, but the 

 material from Ocala when weathered is of a warm yellow. Prob- 

 ably it differs in different places and with the degree of weathering. 

 It is characterized by its profuse foraminiferal fauna and vertebrate 

 remains. 



The " Tampa formation " is believed by Messrs. jNIatson and Clapp 

 to be " contemporaneous " with the Hawthorne and Chattahoochee 

 formations. Whatever may be the case with the two latter, judged 

 by their type localities wdiich have furnished few fossils, the character 

 of the faunas of the different zones of their Tampa formation pre- 

 cludes contemporaneity in the ordinary sense of the word, and the 

 sedimentation shows that the deposition was serial and not contem- 

 poraneous. Doubtless the three so-called " formations! " form a 

 group in which the faunas are more nearly related to each other than 

 to the groups above and below, and this general relation is perhaps 

 what the authors intended to express by the term " contemporaneous." 



The "Alum Bluff formation" of Messrs. Matson and Clapp, as 

 they state,^ is a different group from that named the Alum 

 Bluff beds by Dall in 1892. These authors include in it the Chi- 

 pola marl at the base of the bluff, which faunally is more nearly 

 related to the Tampa Group than to the Oak Grove sands which 

 form paleontologically the characteristic unit of Ball's Alum Bluff 

 beds. The latter were specifically intended to include the strata 

 between the Chipola marl and the Chesapeake (of Dall) or Choctaw- 

 hatchee Miocene of Matson and Clapp. 



The stratimi stratigraphically continuous from Alum Bluff (where 

 it bears no fossils) to Eock Bluff, where it contains Pecten say anus, 

 Turritella alcida, and one or two other species characteristic of the 

 Oak Grove sands, is the representative in Dall's Alum Bluff beds of 

 the sands referred to. The strata between it and the Chipola marl at 

 the foot of the bluff are probably closely related to the marl, though 

 there are very few recognizable fossils. The Oak Grove sands are 

 faunally contrasted with the Chipola marl by the absence of Orthau- 

 lax and many other tropical or warm-water forms which occur 

 abimdantly in the Chipola faima, and by the precursors of the Mio- 

 cene which they contain, such as Pecten sayanus. The Oak Grove 

 sands are of course Oligocene and more nearly related by their fauna 

 to the subjacent Oligocene faunas than to anything which succeeds 

 the sands. But in any grouping of the upper Oligocene faunas that 

 of the Oak Grove sands and the Shoal Eiver fauna reported by 

 Vaughan stands contrasted with those which precede them, though 

 not so markedly as with the succeeding Miocene. 



It may be advisable, considering the misconceptions which have 

 appeared in the writings of some foreign geologists, to put on record 



1 Florida State Geol. Survey, 2nd Ann. Report, 1908-9, p. 91. 



