102 BULLETIN 103, UNITED STATES NATIONAL MUSEUM, 



4. Portion of oblique section showing narrow zone of " lozenge-shaped " 

 equatorial chambers, perforations of peripheral wall of outer equa- 

 torial chambers and perforated pillars among the lateral chambers. 

 X 20. 

 All specimens of L. duplicata from limestone, 2 miles north of David, Panama 

 (station 6523). 



Plate 42. 



Section of limestone from station 6523, 2 miles north of David, showing nu- 

 merous specimens of Lepidocyclina, X 20. Left center, L. panamensis with 

 broad embryonic chambers ; lower middle L. macdonaldi with subspherical em- 

 bryonic chambers ; at right a portion of L. duplicata. 



Plate 43. 



ft 

 Seterosteginoides panamensis, new genus and new species. 



Fig. 1, 2. External view of specimens, X 10, from limy sandstone, east side of 



Gaillard Cut (station 6011). 

 3-6. "Vertical portions, X 20, showing irregular piling of lateral chambers ; 



fig. 6 with two embryonic chambers with thick walls. Specimens 



from limy sandstone near southern switch, Bohio Ridge (station 



6025). 

 7, 8. Horizontal sections, X 20, from same locality at Bohio. 



Nummulites panamensis, new species. 



9. Horizontal section, X 20, from limy sandstone near southern switch, 

 Bohio Ridge (station 6025). 



10. Vertical section from same rock specimen, X 10. 



Nummulites davidensis, new species. 



11. Horizontal section, X 20, from white limestone in river bed above ice 



plant, David, Panama (station 6512). 



Orbitolites americana, new species. 



12-14. Horizontal sections, X 10, specimens from west side of Gaillard Cut, 

 near Las Cascadas (station 6020a). 



Plate 44. 



Orbitolites americana, new species. 



Pig. 1. Horizontal section of large specimen, X 10, from Gaillard Cut, near Las 

 Cascadas (station 6019-6). 

 2. Horizontal section, broken, showing two layers of chambers and inside 

 cast of outer surface, X 20 (station 6020a). 



Plate 45. 



Orbitolites americana, new species. 



Specimen in horizontal section, X 20, showing several areas of breakage and 

 subsequent repair, shown by the angular reentrants of the annuli in various 

 places. From Gaillard Cut, near Las Cascadas (station 6020a). 



