48 SHALLOW-WATER FORAMINIFERA OF TORTUGAS REGION. 



Tnincatulina antillarum (d'Orbigny). 



RotcUina antillarum d'Orbigny, in Do la Sagra, Hist. Fie. Pol. Nat. Cuba, 1839, "Fora- 



minif^res," p. 75, pi. 5, figs. 4 to 6. 

 Truncalxdina anlillanim Cushman, Proc. U. S. Nat. MuB., vol. .)9, 1921, p. .07, pi. 13, figs. 6 to 8. 



Test biconvex, tioclioid, consisting of 4 coils; chambers numerous, rather 

 indistinct on the dorsal side, 7 or 8 in the last-formed coil; sutures on the dor- 

 sal side very oblique, somewhat limbate, not depressed, if anything slightly 

 raised, on the ventral side radiate, from a sliglit umbilical depression; wall 

 thiqk, finely punctate, carinate; aperture an elongate, somewhat curved 

 opening extending from the umbilicus about two-thirds of the way to the 

 periphery on the ventral side of the last-formed chamber, with a slight, thin, 

 overhanging lip, the chamber continuing beyond on tlic periphery, forming 

 an angle in which the outer end of the aperture terminates; color white. 



Diameter of the Tortugas specimens up to 1 mm. 



T. antillarum was found at but two of the station.s in the Tortugas 

 collection, most abundant at station 42, in 18 fathoms, outside of 

 the lagoon. The surface has a peculiar, waxen luster. Although the 

 specimens show the sutures of the test much less clearly than do 

 d'Orbigny's figures, the general characters are the same. I have 

 already recorded this from Montego Bay. D'Orbigny's speci- 

 mens were from Cuba and Jamaica, and the species is probably 

 widely distributed in this general region. The species evidently 

 related to this, occurred fossil in the Coastal Plain of the United 

 States as far back as the Oligocene. 



Tnincatulina cora (d'Orbigny). 



(Plate 7, Figures .3 to 5.) 



Rosalina cora d'Orbigny, Voy. Am6r. M6rid., vol. 5, pt. 5, 1839, " For ami nif feres, " p. 45, 

 pi. 6, figs. 19 to 21. 



Test plano-convex, dorsal side slightly convex, ventral side flattened; com- 

 posed of numerous chambers, usually about 6 in the last-formed whorl; 

 sutures on the dorsal side nearly radiate near the center, thence curving 

 backward, on the ventral side generally radiate, but with pecuUar sinuous 

 curves; wall coarsely punctate; aperture a narrow slit on the ventral side of 

 the last-formed chamber, extending from the periphery of the preceding coil 

 to the umbiUcus; color of the early chambers a very dark brown, gradually 

 becoming lighter, until the last two or three are white. 



Diameter of the Tortugas specimens up to 0.50 nrni. 



This is a species described by d'Orbigny from the coast of Peru, 

 which seems to have had little attention paid to it since. The 

 specimen figured by d'Orbigny is evidently somewhat abnormal, 

 although such specimens occur, as will be seen by a reference to 

 plate 7, figure 5. The most striking features are the very flat 

 lower side and the peculiar sinuous curves on the sutures of the 

 ventral side. The ventral side of the test, although each chamber is 

 flattened, is not a single plane, each chamber level being raised 

 slightly above the preceding. The species has not been common in 

 the area. It seems to be related to T. candeiana d'Orbigny, the 



