NO. 5 FORAMINIFERAL GENERA — LOEBLICH AND TAPPAN 25 



Diagnosis. — Test free, elongate, narrow, slightly arcuate, of nearly- 

 equal diameter throughout, no regular chamber arrangement, but with 

 a spiraling internal column, which gives an extremely irregular septa- 

 tion as it spirals and occasionally touches the exterior wall ; wall cal- 

 careous, finely perforate with radial structure, aperture subterminal, 

 ovate, just above a sutural junction. 



Types. — Holotype (B.M.N.H. No. ZF 2064) from Challenger sta- 

 tion 219A, at 17 fathoms. Admiralty Islands. Dissected hypotype here 

 figured (B.M.N.H. No. ZF 3630) from F. W. Millett Collection, 

 Challenger station 185, off Raine Island, Torres Strait, at 155 fathoms. 



Discussion. — Orthoplecta was originally defined as a subgenus of 

 Cassidulina d'Orbigny, 1826. However, there is no cassiduline early 

 portion, and the later part is neither biserial nor irregularly biserial. 

 Interestingly, Wood (1949, p. 244) noted that Orthoplecta clavata had 

 a perforate radial structure, unlike the majority of the Cassidulinidae 

 which have a perforate-granular structure. This difference in wall 

 structure supports the separation of Orthoplecta from the Cassidulini- 

 dae and suggests its placement perhaps with the Ceratobuliminidae. 



Genus CIBICIDOIDES Thalmann, 1939 

 Plate 4, figure 4 



Original description. — Originally described by Brotzen (1936, pp. 

 186, 194), but as Brotzen did not designate a type species the genus 

 was invalid until Thalmann designated the type in 1939, p. 448. 



Type species. — Truncatulina mimdida Brady, Parker, and Jones, 

 1888. Subsequent designation by Thalmann (1939, p. 448). 



Diagnosis. — Test free, trochoid, biconvex and biumbonate, all cham- 

 bers visible dorsally, only those of the final whorl visible ventrally; 

 wall calcareous, hyaline, with a series of coarse perforations on the 

 dorsal side, appearing only near the previous spiral suture in the early 

 portion of the test, but covering a large portion of the dorsal side of 

 the later chambers ; aperture at the base of the apertural face of the 

 final chamber, against the peripheral margin of the preceding whorl, 

 consisting of a low arch with a slightly projecting lip. 



Types. — Lectotype, here designated (B.M.N.H. No. ZF 3585), and 

 paratypes (B.M.N.H. No. ZF 3584), all from Plumper station 4, at 

 260 fathoms, lat. 22°54' S., long. 40° 37' W., over Abrohlos Bank, off 

 the coast of Brazil, South America. 



Discussion. — Cibicidoides was originally described as a subgenus of 

 Cibicides by Brotzen (1936, pp. 186, 194), but as he did not at that 

 time designate a type species, the genus was invalid. He cited two 



