554 BULLETIN" 103, UNITED STATES NATIONAL MUSEUM. 



The identification of deposits within the Canal Zone as belonging 

 to the Culebra formation needs brief discussion. The type sections 

 are in Gaillard Cut, particularly at station 6020a to 6019/ (see p. 538 of 

 Doctor MacDonald's paper), and beds Nos. 1-5, inclusive, of the 

 section on the west side of the cut between Empire and Culebra. 

 The collections from 6020c to 6019/ are typical of the upper part of 

 the formation; those from 6012a typify its lower part, while those 

 from 6012c and 6012a 1 represent its upper part (p. 536 of Doctor Mac- 

 Donald's paper). He refers the beds that were exposed at stations 

 6009 and 6010 to the lower part of the Culebra, and those at stations 

 6011 to the upper part. In Gaillard Cut Lepidocyclina chaperi occurs 

 at station 6019/ and L. canellei at station 6019a; in other words 

 both of these species occur in the upper part of the Culebra formation,, 

 the latter below the former. Heterosteginoides panamemsis occurs at 

 station 6011 in the upper part of the Culebra formation and apparently 

 it was also obtained at stations 6015 and 6016 in the overlying Em- 

 perador limestone. As at station 6024a, on Rio Agua Salud, immedi- 

 ately benaath a coralliferous bed representing the Emperador lime- 

 stone, Heterostigenoides panamensis and Nummulites panamensis 

 were collected, both the stratigraphic relations and the fossils support 

 the reference of the lower bed to the upper part of the Culebra forma- 

 tion. At Bohio switch, station 6025, Lepidocyclina cliaperi and 

 Nummulites panamensis were found in association. This bed also 

 may be referred to the upper part of the Culebra formation. At 

 station 6026, about 2 miles south of Monte Lirio, Lepidocyclina canellei 

 and a species of Nummulites, apparently N. panamensis, were found 

 associated with fossil corals closely related to the fauna of the Em- 

 perador limestone on one hand, and to that of the Antigua formation 

 of Antigua on the other; and Orihaulax pugnax was collected there. 

 The correlation of this exposure with the Culebra formation, probably 

 about its middle part, seems as certain as it is possible to be in such 

 matters. The principal locality for Lepidocyclina canellei was near 

 the old town of Bohio, station 6027, now under water. It was here 

 that Hill obtained his specimens of " Orbitoides forhesi," which are i. 

 canellei, and it is probable that the type of the species came from the 

 same place. The deposit here so rich in this species of Foraminifera 

 is referred to the Culebra formation, as are also the beds in which it 

 was obtained at Bailamonas and south of the switch at Mamei. 



DEPOSITS OF THE AGE OF THE CULEBRA FORMATION NEAR TONOSI. 



The only organisms of those collected by Doctor MacDonald in this 

 area that have been studied are the Foraminifera and the corals* 

 The following is a table of the larger Foraminifera: 



