GEOLOGY AND PALEONTOLOGY OP THE CANAL ZONE. 221 



Berry has recently reviewed the Miocene Calvert flora of Maryland 

 and Virginia, and expressed the following opinion:^ 



Seven of the Calvert plants, or 26.9 per cent, are common to the Tortonian of Europe, 

 and 10 others, or 38 per cent, are represented in the Tortonian by very similar forms. 

 In view of the fact that these floras spread into both regions from a common and equally 

 accessible source, as I have just stated, the eAddence that the Calvert flora indicates 

 a Tortonian age is as conclusive as intercontinental correlations can ever be. Com- 

 pared with other American floras of Miocene age, that of the Calvert has little in com- 

 mon with the described Miocene floras from Colorado, Idaho, Oregon, or California, 

 which are all lake or river valley floras of moist upland forest types. 



Should Berrj^ be correct in his correlation of the Calvert with the 

 European Tortonian, there is at present no deimitely recognized 

 Helvetian Miocene m the Coastal Plain of the United States; and con- 

 sequently no Helvetian coral-fauna. 



COSTA RICA. 



Corals representing the Bowden horizon or one ver}'- near it were 

 obtained in Costa Rica at two localities, viz: 



"Limon, Colline en demolition," No. 618 of the H. Pittier collection; 

 and at station 6249, Hospital Point, Bocas del Toro. The species 

 from the former of these localities are as follows : 



Asterosmilia TiiUi Vaughan. 

 Steplianocoenia intersepta (Esper). 

 Dichocoenia tuberosa Duncan. 

 BalanGphyllia pittieri Vaughan. 



BalanopliyTLia. pittieri was obtained at Hospital Point as well as 

 at Port Limon. 



PANAMA. 



The type of StylopJiora portohellensis Vaughan, from Portobello, 

 was probably collected in the Gatun formation. 



COLOMBIA. 



Mr. George C. Matson collected at a locality 0.5 kilometer east of 

 Usiacuri in association with a fauna representing the Gatun forma- 

 tion specimens of Septastrea maisoni Vaughan, which is very nearly 

 related to Septastrea marylandica (Conrad) — a species common in 

 the St. Marys and Yorktown Miocene of Virginia. The available 

 evidence leads to the opinion that the Gatun formation is of Miocene 

 age, and that part of it is of upper Miocene age. 



CONCLUDING REMARKS ON THE MIOCENE. 



The Gatun formation, the formation next above the Emperador 

 limestone, according to the geologic map, plate 153, occm's only on 

 the north flank of the Isthmus and does not extend from ocean to 

 ocean. There is in the Canal Zone no evidence to indicate inter- 



1 U. S. Geol. Survey Prof. Pap. 98-F., p. 66, 1916. 



