STUDIES IN FOBAMTNIFERA 



39 



found to be distinctly radial, as in Olobigerina. Fur- 

 thermore, Candeina also has a radial wall structm-e. 

 No suggestion of "toothplates" was seen in either genus, 

 unless Hofker referred to the typical lip as a toothplate. 



Hofker considered Globigerinatella to be related to 

 "Quadrimorphina, Pvllenoides, Candeina and possibly 

 also with Chilostomellina." As has been shown earlier 

 (Loeblich and Tappan, 1953, p. 93), Chilostomellina has 

 a granular wall structure, and a planispiral plan of 

 coiling, and thus is quite distinct from these trocho- 

 spiral forms with radially built walls. 



Globigerinaklla is considered to belong imquestion- 

 ably to the Orbulinidae. It is related to Olobigerina, 

 as shown by the early trochospiral stages with a single 

 umbilical aperture, and to Orbulina in having the strong- 

 ly embracing final chamber with areal and sutm-al 

 secondary apertiu-es. It differs from Globigerina in 

 the presence of the bullae and accessory apertures, and 

 from Orbulina in having the early stage also with areal 

 apertures. 



Types and occurrence: Holotype of Globigerina- 

 tella insueta Cushman and Stainforth (Cushman Coll. 

 44040), paratypes here figm-ed (Cushman Coll. 44043a, 

 b) and unfigiu-ed (Cushman CoU. 44041, 44042, and 

 44043) ; figured topotypes (USNM P3932a, b) and un- 

 figured topotypes (USNM P3931 and P3936) from the 

 Cipero formation, Globigerinatella insueta zone (Mio- 

 cene), Cipero Coast section, Trinidad, B. W. I. Topo- 

 types collected by H. M. Bolli. 



Range: Miocene. 



Family Globorotaliidae Cushman, 1927 



Type genus: Globorotalia Cushman, 1927. 



CoUing of test trochospiral; chambers angular to 

 ovate or spherical; waU calcareous, perforate, radial in 

 structure; primary aperture extraumbilical-umbilical, 

 may have secondary sutural apertures on spiral or 

 lunbihcal side. 



Range: Cretaceous to Recent. 



G^enus Praeglobotruncana Bermudez, 1952 



Plate 9, Figures la-4o 



Praeglobotruncana Bermudez, Venezuela Minist. Minas, Bol. 

 Geol., vol. 2, No. 4, p. 52, 1952. 



Rotundina Subbotina, Trudy Vses. Neft. Naukno-Issledov. 

 Geol.-Razved. Inst., n. ser. 76, p. 165, 1953. (Type species: 

 Globotruncana stephani Gandolfi, 1942. Fixed by original 

 designation.) 



tHedhergina Bronnimann and Brown, Eclog. Geol. Helvetiae, 

 vol. 48 (1955), No. 2, p. 529, 1956. (Type species: Globi- 

 gerina seminolensis Harlton, 1927. Fixed by original desig- 

 nation and monotypy.) 



Type species: Globorotalia delrioensis Plummer, 

 1931. Fixed by original designation. 



Test free, trochospiral, biconvex to spiroconvex, 

 umbilicate, periphery rounded to subangular, or with a 

 moderate keel ia the early stages, commonly progres- 

 sively less prominent in the later development; cham- 

 bers globular, ovate or subangular; sutures on the spiral 

 side depressed to elevated and thickened or even 



beaded, radial or curved, on the umbilical side de- 

 pressed and radial; wall calcareous, finely perforate, 

 radial in structure, surface smooth to hispid; aperture 

 interiomarginal, a relatively high and open extra- 

 umbilical-umbilical arch bordered above by a narrow 

 lip or spatulate flap commonly directed toward the 

 umbUicus, and in forms with a broad open umbilicus 

 successive apertural flaps may remain visible to present 

 a serrate or scalloped border around the umbilicus. 



Remarks: Although the type species of Praeglobo- 

 truncana had been originally described as belonging to 

 Globorotalia, Bermudez did not give any comparisons 

 of his proposed new genus to Globorotalia, but con- 

 sidered it ancestral to Globotruncana, because of its 

 having a more open umbiHcus. Bermudez did not 

 describe the apertural characters completely, stating 

 only that the aperture was a simple groove in the base 

 of the septal face of the final chamber (i. e., interio- 

 marginal). In the type species selected, the apertiu^e, 

 like that of a typical Globorotalia, consists of an extra- 

 lunbilical-umbilical arch bordered by a hp. It is 

 perhaps somewhat more open and directed more in an 

 xunbilical direction. 



Rotundina Subbotina, 1953, (with Globotruncana 

 stephani Gandolfi as type species) was said by the 

 describer to be characterized by an open umbUicus and 

 apertiu-e situated near the umbilical ends of the cham- 

 bers, extending for some distance along the peripheral 

 suture. Near the lunbflicus an outgrowth of the wall 

 was said to be present that, taken together, produced a 

 wide rim or border sui-rounding the mnbilicus. Reichel 

 (1949) had provisionally placed Globotruncana stephani 

 Gandolfi in Globotruncana, s. s., although stating that 

 it could equally well be placed in Globorotalia. He 

 figured a specimen that shows an umbihcus bordered 

 by such a scalloped lamellar expansion. On topotypes 

 obtained from Reichel, this feature is not evident and 

 sutmes are radial into the open umbilicus. However, 

 a suite of specimens of Praeglobotruncana delrioensis 

 (Plummer) included a few possessing large and well- 

 developed apertural lips. These projected somewhat 

 above the normal curvature of the chamber, so that the 

 final Up, together with the earher ones, presented an 

 irregular umbihcal margin. This represents the feature 

 mentioned by Subbotina and Reichel and may also be 

 observed in occasional specimens of many of the other 

 species of Praeglobotruncana. A specimen of P. plani- 

 spira (Tappan) is here figured which excellently demon- 

 strates this feature. Thus, Rotundina stephani and 

 Praeglobotruncana delrioensis possess identical apertural 

 characteristics, and as they are congeneric, Rotundina 

 Subbotina is suppressed as a junior synonym. 



Bermudez also included Globotruncana appenninica 

 Renz in Praeglobotruncana, but this species is a true 

 Rotalipora as has been noted by Reichel (1949, p. 604), 

 Sigal (1952b, p. 24), Hagn and Zeil (1954, p. 22) and 

 Kiipper (1955, p. 114). A specimen figiu-ed here also 

 shows the well developed secondary sutural apertures 

 typical of Rotalipora. 



Hedbergina was described by Bronnimann and Brown 



