FURAMIXIFERA OF THE BYRAM CALCAREOUS MARL AT BYRAM, MISS. 



97 



tricately lobed, the chambers themselves of 

 lighter color, the sutures darker, of clear shell 

 material; surface finely granular; aperture an 

 elongate opening at the base of the last^formed 

 chamber near its inner ventral border. Diame- 

 ter 0.35 to 0.75 millimeter. 



This species is rather common in the marl at 

 Byram. In the form of the lobed chambers it 

 is related to two other Miocene species I have 

 described — T. &(2s??o6a, from South Carolina, and 

 T. concentrica, from the Choc tawha tehee marl 

 of Florida. In the peculiar labyrinthic form 

 of the chamber it is not unlike some forms of 

 Pnlvinulina elegans D'Orbigny, but the shape 

 of the test, chambers, and aperture is different. 



Truncatulina americana Cushman. 



PKafe XX, figures 7. S. 



Truncatulina americana ('ushman, U. S. Geol. Survey 

 Bull. 676, p. 63, pi. 20, figs. 2, 3; pi. 21, fig. 1, 191S; 

 U. S. Nat. Mus. Bull. 103, p. 68, pi. 23, figs. 2a-c, 

 1918. 



Test planoconvex, dorsal side nearly flat, 

 ventral side slightly convex, chambers numer- 

 ous, ten to fifteen in the last-formed coil, 

 rather rapidly increasing in size, peripheral 

 margin subangular, dorsal side ^vith the last 

 few chambers failing to meet the umbilicus, 

 ventral side similar in this respect in most 

 specimens; sutures distinct, slightly limbate on 

 the dorsal side, depressed on the ventral side; 

 wall smooth, punctate, aperture peripheral with 

 a slight lip. Diameter 0.75 millimeter or less. 



This species is not so conunon in the Byram 

 marl as in the Miocene deposits. It is kno\\^l 

 from the Choctawhatchee marl at Coes Mills 

 and Jackson Bluff, Fla., the Duplin marl at 

 Mayesville, S. C, and Wilmington, N. C, the 

 Yorktown formation at Yorktown, Va., and 

 the Choptank formation at Jones Wharf, Md. 

 I have also recorded it from the lower Miocene 

 of Florida and from the upper Oligocene 

 Culebra formation of the Canal Zone. It is 

 found in the Miocene penetrated by wells in 

 different parts of the peninsula of Florida. 



Truncatulina pseudoungeriana Cushman, n. sp. 



Plate XX, figure 9. 



Truncatulina ungeriana H. 15. Brady (not Rotalina un- 

 ^friana D'Orbigny, 1826), Challenger Rept., Zoology, 

 vol. 9, pi. 94, figs. 9a-c, 1884. 

 Cuphman, U. S. Nat. Mus. Bull. 103, p. 69, pi. 24, 

 fig. 1, 1918. 



Test biconvex, almost equally so; periphery 

 subacute, chambers nine to eleven in the last- 



formed whorl, those of (he earlier whorls not 

 showing on the dorsal side because they are 

 hidden by the roughness of the surface, or on 

 the ventral side because of the involute charac- 

 ter: periphery lobulated; sutures distinct above 

 in the last whorl and very distinct below, as the 

 sutures are somewhat tumid on the ventral 

 side; umbilical region filled nearly flush with 

 the chambers by clear shell material, last few' 

 chambers on the dorsal side slightly above the 

 surface on the inner margin: surface dorsally 

 with coarse punctae, below smooth and more 

 finely punctate; aperture at the periphery. 

 Diameter 1 millimeter or less. 



In the BjTam marl the same form appears 

 that is figured by Brady as T. ungeriana. Brady 

 says of his figure, "The drawing (PI. XCIV, 

 fig. 9) is not a good illustration of the species, 

 the specimen being relatively thicker and al- 

 together more stoutly built than the typical 

 form." A comparison of Bra(l\-'s figure with 

 that given by D'Orbigny in the Vienna Basin 

 monograph will show the numerous differ- 

 ences in the two. Brady does not give the 

 locality for the specimen from which his draw- 

 ing was made, but I have seen identical mate- 

 rial from the Philippine and Australian regions. 

 The occurrence of this same form in the Byram 

 marl seems to show that the species is distinct 

 and that discrimination will show it to have a 

 definite geographic range in the present ocean. 

 Material from the Oligocene Culebra formation 

 of the Canal Zone that I have referred to T. 

 ungeriana may be this new species. 



Genus ANOMALINA D'Orbigny. 

 Anomalina bilateralis Cushman, n. sp. 



Plato XXI. figures 1, 2. 



Test of about four coils, bilateral or nearly so, 

 composed of numerous chambers, ten or more 

 in the last-formed whorl, umbilical region on 

 both sides with a knob of clear shell material, 

 more pronounced on the dorsal side, chambers 

 smooth but coarsely punctate, more coarsely 

 so on the ventral side, sutures broad and some- 

 what limbate with clear shell material: aper- 

 ture a narrow curved opening at the base of the 

 final chamber. Diameter 1 millimeter or less. 



This form is rare in the Byram marl. It is 

 close to .4. ammonoides Reuss but differs from 

 that species as figured by Reuss. It is very 

 close to the form figured in the Challenger report 

 by Brady (pi. 94, fig. 2). The Challenger mate- 

 rial in which Brady found it was almost entirely 



