GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 65 



in argillaceous and sandy indurated marl, one-fourth to one-half 

 mile north of Camp Cotton on relocated line, Panama Railroad; 

 6033c in marl from second bed from bottom, just below lower clay, 

 Gatun Section relocated line, Panama Railroad; 6035, in gray green, 

 fine grained, sandy shell marl, near Mindi Hill; and 6036, in dark 

 colored, fine grained, sandy clay marl, Monkey Hill, Mount Hope 

 Station. 



The specimens from the last three stations are very well preserved 

 and in fact might almost be recent material, while those of the other 

 stations were fragmentary, often glauconitic. G. bulloides, var. 

 triloba Reuss was occasional in the last three stations where the 

 genus was really very common. 



GLOBIGERINA INFLATA d'Orbigny. 



Globigerina inflata d'Orbigny, in Barker, Webb, and Berthelot, Hist. Nat. 

 Isles Canaries, vol. 2, pt. 2, 1839, Foraniiniferes, p. 134, pi. 2, figs. 

 7-9.— H. B. Brady, Rep. Voy, Challenger, Zoology, vol. 9, 1884, p. 601, 

 pi. 79, figs. 8-10. 



Description. — Test composed of numerous inflated chambers usu- 

 ally arranged in a spiral test with about three volutions, the last- 

 formed one with four chambers, dorsal side of test nearly flat, ventral 

 side extended, especially in the last-formed whorl; ventrally umbili- 

 cate; surface finely reticulate; aperture large, opening toward the 

 umbilicus. 



Diameter, 0.75 mm. Cat. Nos. 324647, 8, 9, U.S.N.M. 



Specimens occurred at U.S.G.S. No. 6010, lower part of the Cule- 

 bra formation, in dark clay north of Pedro Miguel Locks; and in 

 the Gatun formation at the last two of the stations already referred 

 to, namely, 6035 and 6036. 



GLOBIGERINA DUBIA Egger. 



Globigerina dubia Egger, Neue.s Jahrb. fur Min., 1S57, p. 281, pi. 9, figs. 

 7-9.— H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 595, 

 pi. 79, figs. 170-c. 



Description: — Test composed of numerous inflated chambers ar- 

 ranged in a naut'iloid spiral all visible from above, the last coil only, 

 consisting of 5 to 6 chambers, visible from below, ventral side with a 

 central umbilicus, surface reticulate; apertures opening into the 

 central umbilical cavity. 



Diameter 0.75 mm. Cat. Nos. 324650-54. 



At the following stations specimens referable to this species were 

 found: Culebra formation, U.S.G.S. No. 6010, in dark clay, north 

 of Pedro Miguel Locks; 6025, in dark, hard, sandy clay about 200 



