20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 28 



this British form can be easily recognized by the low conical test with 

 three chambers in the last whorl. Cushman defined Trochamminella 

 in 1943, but as T. siphonifera is congeneric with Rotalina fusca, the 

 name Trochamminella is a junior synonym of Tritaxis Schubert, 1920, 

 and must therefore be suppressed. 



Genus TROCHAMMINELLA Cushman, 1943 



Plate 3, figure 7 



Original description. — Contr. Cushman Lab. Foram. Res., vol. 19, 

 pt. 4, p. 95, 1943- 



Type species. — Trochamminella siphonifera Cushman, 1943. Orig- 

 inal designation. 



Diagnosis. — See under Tritaxis Schubert, 1920. 



Types. — Holotype (U.S.N.M. Cushman Coll. No. 39619) from the 

 Johnson-Smithsonian Expedition station 25, lat. i8°32'i5" N., long. 

 66°22'io" W., at 240 to 300 fathoms, off Puerto Rico. 



Discussion. — Cushman described Trochamminella as a specialized 

 development from Trochammina, differing in the apertural characters. 

 He figured both an unattached form with the ovate rimmed aperture, 

 and an attached specimen surrounded by an irregular rim of material 

 which extended at one side with an almost tubular protrusion, ending 

 in a rounded opening. As can be seen from the figures, however, this 

 form is identical with the genus Tritaxis Schubert, 1920 (type Rotalina 

 fusca Williamson) ; hence Trochamminella Cushman, 1943, must be 

 suppressed as a junior synonym. 



Genus ROTALIAMMINA Cushman, 1924, emended 

 Plate 3, figure 4 



Original description. — Carnegie Inst. Washington, Publ. 342 (Dept. 

 Marine Biol. Papers, vol. 21), p. 11, pi. i, figs. 4, 5, 1924. 



Type species. — Rotaliammina mayori Cushman, 1924. Original 

 designation. 



Diagnosis. — Test attached, trochoid, all chambers visible dorsally, 

 only those of the final whorl seen from the attached ventral side, 

 ventrally umbilicate; wall very thin, agglutinated, with fine sand held 

 in a small amount of cement; aperture indistinct, probably ventral. 



Types. — Holotype (U.S.N.M. Cushman Coll. No. 511) from station 

 9, 50 fathoms, south of Breaker Point, between mouth of Pago Pago 

 Harbor and Taema Bank, Tutuila, Samoa. Collected by A. G. Mayor. 



Discussion. — The type species was originally described as having 



