STUDIES m FORAMINTFBRA 



231 



Parker and Jones' original description (1857, p. 294) 

 stated that A. coronata "affects a bilateral symmetry, 

 the two surfaces being often nearly equal," and this 

 character is sho^vn in their illustrations. Asano also 

 placed Rotalina semipunda BaUey, 1851, in Discano- 

 malina, and this species is correctly assigned, having 

 the clear shell material and chamber flaps only on 

 one side, with the opposite side entu-ely coarsely 

 perforate. 



Paromalina bilateralis Loeblich and Tappan, new species 

 Plate 73, Figures 12, 13 



Test, free, planispiral, biumbUicate, very thick, with 

 broad truncate periphery, early whorls obscured on 

 both sides, seven to nine chambers in the final whorl, 

 about equal in breadth and height, but with much 

 greater thickness, truncate on the periphery and 

 laterally inflated, chambers with an umbilical flap on 

 each side that extends backward over the previous 

 suture and toward the umbilicus to cover earlier whorls, 

 rarely coalescing with those of other chambers to 

 obscure the more commonly open umbilicus; sutures 

 distinct, radial, depressed; waU calcareous, smooth, 

 very coarsely perforate on the truncate peripheral 

 portion of the chambers, but the sides and umbilical 

 flaps and the apertural face are clear and apparently 

 imperforate, and commonly a small imperforate area 

 formed by the peripheral portion of the previous septal 

 face is left exposed just behind the suture when the next 



chamber is added, giving an erroneous impression of 

 thickened imperforate sutures, although the actual 

 sutures are depressed; apertm-e a broad low slit at the 

 base of the final chamber on the periphery and against 

 the preceding whorl, bordered above by a slight lip, 

 with supplementary openings beneath the umbilical 

 and posterior margins of the umbilical chamber flaps 

 on each side of the test. 



Greatest diameter of holotype 0.78 mm., least diam- 

 eter 0.68 mm., greatest thickness 0.65 mm. Paratypes 

 range from 0.70 to 0.99 mm. in greatest diameter. 



Remarks: This species is very similar to Anomalina 

 coronata Parker and Jones, but neither their original 

 illustration nor that of Brady (1884, pi. 97, figs. 1 and 

 2) show the large and distinctive flaps, covering the 

 umbilical region and obscuring the earlier whorls, that 

 are characteristic of the present species. Much 

 smaller flaps are shown by Brady, but a portion of the 

 previous whorl is left exposed on both sides. The 

 figure given by Parker and Jones (1857, pi. 10, fig. 15) 

 is too small to show these details clearly, but they also 

 show the earlier whorls visible in the umbilical region. 



Types and occurrence: Holotype (USNM P4883) 

 and unfigured paratypes (USNM P3216) from the 

 Recent, Albatross Station D2262, lat. 39°54'45" N., 

 long. 69°29'45" W., at 250 fathoms. 



Figured paratype (USNM P3137), unfigured para- 

 types (USNM P3136 and P3138) from F. C. Goldseeker 

 Station 16, Haul 89, lat. 62° N., long. 6°12' W., at 128 

 meters. Collected July 8, 1907. 



References 



Asano, K. 



1951, Illustrated catalogue of Japanese Tertiary smaller Foraminifera. Ft. 13, Anomalinidae. 

 Petroleum Branch, Natural Resources Section, General Headquarters, Supreme Com- 

 mander for Allied Powers, pp. 12-19. 

 Barnard, T. 



1949. An abnormal Chalk foraminifer. Proc. Geol. Assoc., vol. 60, pp. 284-287, pi. 12. 

 Brady, H. B. 



1884. Report on the scientific results of the voyage of H. M. S. Challenger, Zoology, vol. 9, pp. 1-814, 

 pis. 1-115. 



CUSHMAN, J. A. 



1918. The Foraminifera of the Atlantic Ocean. U. S. Nat. Mus. Bull. 104, pt. 1, Astrorhizidae, 



pp. 1-111, pis. 1-39. 

 1931. The Foraminifera of the Atlantic Ocean. U. S. Nat. Mus. Bull. 104, pt. 8, Rotaliidae, 

 Amphisteginidae, Calcarlnidae, Cymbaloporettidae, Globorotaliidae, Anomalinidae, 

 Planorljulinidae, Rupertiidae and Homotremidae, pp. 1-179, pis. 1-26. 

 CnsHMAN, .7. A., and Jarvis, P. W. 



1929. New Foraminifera from Trinidad. Contr. Cushman Lab. Foram. Res., vol. 5, pp. 6-17, 

 pis. 2, 3. 

 Cushman, J. A. and Parker, F. L. 



1947. Bidimina and related foraminiferal genera. U. S. Geol. Surv., Prof. Pap. 210-D, pp. 55-176, 

 pis. 15-30. 



HOFKER, J. 



1951. The Foraminifera of the Siboga expedition. Siboga-'Expeditie, pt. 3, pp. 1-513. 



