GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 67 



Specimens were not uncommon in material from the Gatun forma- 

 tion at stations 6035 and 6036. As in the case of G. conglobata the 

 specimens were hardly as well developed as they are in recent speci- 

 mens, but nevertheless had the characteristic marks of the species. 

 As in G. conglobata the records of this species are almost entirely 

 limited to Recent material, its occurrence as a fossil being practically 

 unknown. 



GLOBIGERINA AEQUILATERALIS H. B. Brady. 



Cassidulina globulosa (part) Eggeb, Neues Jahrb. fiir Min., 1857, p. 296, 



pi. 11, fig. 4. 

 Globigerina aequilateralis H. B. Beady, Quart. Jo-urn. Micr. Sci., vol. 19, 



1S79, p. 71; Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 605, pi. 80, 



figs. 18-21. 



Description. — Test composed of numerous inflated chambers, ar- 

 ranged in a planospiral manner, at least the last formed coil, cham- 

 bers increasing rapidly in size as added, usually 5 to 6 in the last 

 formed volution; sutures depressed, periphery lobulated; surface 

 reticulate; aperture large, at the base of the inner margin of the 

 chamber. 



Diameter up to 1 mm. Cat. Nos. 324659-61, U.S.N.M. 



In the material from the Gatun formation at three stations, Nos. 

 6033c?, 6035, 6036, this species was not uncommon. The only char- 

 acter in which there seems to be a difference from the Recent material 

 is in the early chambers which occasionally show at one side as a flat 

 spiral while the later chambers are bilateral. The species is not a 

 common one as a fossil. 



Genus ORBULINA d'Orbigny, 1839. 



ORBULINA UNIVEKSA d'Orbigny. 



Orbulina universa d'Oebigny, in De la Sagra, Hist. Fis. Pol. Nat. Cuba, 

 1839, Foraniiniferes, p. 3, pi. 1. fig. 1.— H. B. Beady, Rep. Voy. Chal- 

 lenger, Zoology, vol. 9, 1884, p. 608. pi. 78; pi. 81, figs. 8-26: pi. 82, 

 figs. 1-3. 



Description. — Test in adult form typically consisting of a single, 

 spherical visible chamber, which may or may not have contained 

 within the early Globigerine stages ; wall strongly reticulate, a single 

 large circular aperture and smaller openings at the base of each 

 reticulation. 



Diameter up to 1 mm. Cat. Nos. 324662-3, U.S.N.M. 



Specimens were not uncommon in the Gatun formation at the 

 three stations, Nos. 6033c, 6035, and 6036. Occasional specimens 

 show the double form as figured by Brady. The specimens other- 

 wise are like the common run of Recent material. 



