578 BULLETIN" 103, UNITED STATES NATIONAL MUSEUM. 



Priabonian ago. Miss Maury * correlates the basal bed of the ex- 

 posure at Soldado Rock, Trinidad, with the Midway group of the 

 Gulf Coastal Plain of the United States, but I am not convinced that 

 the fauna is quite so old. In fact, the paleontologic evidence seems 

 to me just about as strongly in favor of the horizon corresponding to 

 one in the WilcOx group. Douville is of the opinion that most of 

 Miss Maury's horizons are younger than the age she has assigned 

 them. There are discrepancies between Miss Maury's and Douville's 

 correlations that probably can be reconciled only by a critical study 

 of Foraminifera positively known to be associated with the respec- 

 tive beds in which the Mollusca were collected. I have had con- 

 siderable experience in checking M. Douville's results, and, except 

 that he does not understand all of the stratigraphic nomenclature 

 and is greatly confused as to some of the stratigraphic relations in 

 the southeastern United States, I have usually found his deductions 

 as to the age of formations valid. It seems to me that the table in 

 his last paper on the Trinidad orbitoids is correct, except that it seems 

 to me more appropriate to refer the Aquitanian to the Oligocene than 

 to the Miocene. 



OLIGOCENE. 



LOWER OLIGOCENE. 



The quotation, page 549, from Douville indicates tho proscnco on tho 

 Haut Chagres of limestone of lower Oligocene (Lattorfian) ago, as it 

 contains specimens of Orihophragmina (Asierodiscus) species in 

 association with Lepidocyclina species resembling L. cliaperi. 



Doctor MacDonald collected in tho river bed at David, station 6512, 

 Lepidocyclina macdonaldi, L. duplicaia, L.panamensis, Orilwpliragmina 

 minima, and Nummulites davidensis; at station 6526, in limestone 

 which according to his section immediately underlies tho lime- 

 stone at station 6512, where ho obtained Lepidocyclina spocies unde- 

 termined and Nummuliles davidensis; and ho found at station 6523, 2 

 miles north of David, Lepidocyclina macdonaldi and L. duplicaia. 

 These three localities represent very nearly, if not precisely, tho same 

 horizon, and havo faunal characters very similar to those of tho 

 horizon in Trinidad that Douville correlates with the "Stampien 

 inferiour," which, according to him, is Lattorfian. It therefore seems 

 that tho limestone in and north of David is of lower Oligocene (Lat- 

 torfian) ago, and is the correlative of tho Vicksburg group of tho 

 eastern Gulf States of the United States. Doctor Cushman's opin- 

 ions as to the probable Eocene ago of this limestone was given on 

 page 550. 



It is probable that the Bohio conglomerate is of this ago, for it 

 contains the Oligocene plant, Taenioxylon muliiradiaium Felix, which 



i Maury, C'arlotta J., A contribution to the paleontology of Trinidad, Acad. Nat. Sci. Philadelphia 

 Journ., ser. 2, vol. 15, pp. 25-112, pis. 5-13, 1912. 



