﻿GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 



557 



The echinoid, Clypeaster gatuni Jackson, is worth a special note. 

 The holotype is from the Gatun formation, station 5662, but two 

 specimens were also collected at station 6237, in limestone referred 

 by Doctor MacDonald to the Emperador limestone, in a swamp 

 north of Ancon HiU and about 4 miles south of Diablo Ridge. This 

 species extended from the Atlantic to the Pacific side of the Isthmus. 



Doctor MacDonald and I obtained at station No. 6019$r two poor 

 crushed specimens of a gastropod that belongs to the genus Orthaulax. 



A few remarks should be made on the reference of the limestone 

 exposed at station 6021 near the old Caimito switch, to Emperador 

 limestone. Only two identifiable species, Lithothammium isthmi 

 and Lepidocyclina vaugJiani, were obtained at this place, but both 

 were found elsewhere in the Emperador Umestone. Lithothammium 

 isthmi was also collected on Rio Agua Salud, station 60246, in 

 association with a coral fauna very nearly the same as that at th© 

 type locality of the formation; and Le/pidocyclina vaughani was 

 obtained in the Emperador limestone near Miraflores. 



FOSSILS FEOM THE EMPERADOB UMESTONE. 



