STUDIES m FORAMINIFERA 



21 



Unfortunately, published records are not always 

 reliable. Foraminifera have been recorded at times 

 from misdated horizons, or in other instances from 

 beach sands or Eecent deposits which also include 

 reworked fossil material. In other instances the too- 

 wide limits set for genera and species suggest a much 

 wider geologic range than is actually the case. Thus, 

 in order to use stratigraphic occurrence as a tool in 

 classification, many of these records have had to be 

 critically re-examined. 



The tabulation in text-figure 9 shows the strati- 

 graphic ranges of the genera of planktonic Foraminifera 

 as here defined. As can be seen, many of the genera 

 are more restricted in geologic range than has hitherto 

 been suspected. The actual placement of the various 

 species is not attempted in the present paper, but wiU 

 appear in later pubUcations of this series. 



Summary 



In the present revision the following characters have 

 been used for classification: 



Family characters: The wall composition and 

 structure, general chamber arrangement (i. e., type 

 of coiling), basic position of primary aperture (in 

 adult of simpler forms, in ontogeny of specialized 

 forms). 



Subfamily characters: Presence or absence of 

 apertural modifications, modifications in chamber 



arrangement (i. e., changes in type of coiling) and 

 presence or absence of chamber modifications. 

 Generic characters: Position, shape and character 

 of aperture in the adult, presence or absence of 

 chamber modifications, and general form and de- 

 velopment of the test. 

 Specific characters: Size; relative proportions of 

 test, chambers and aperture, etc.; and surface 

 ornamentation. 

 The resultant classification here presented is similar 

 to that of Cushman in recognizing the families Hant- 

 keninidae, Globorotaliidae and Orbuhnidae (which has 

 priority over the name Globigerinidae). The main 

 differences lie in the separation of Globotruncana from 

 the Globorotaliidae and Rugoglobigerina from the Glo- 

 bigerininae into a separate family — the Globotrun- 

 canidae (which has been done by Bronnimann and 

 Brown, 1956, although they also included various genera 

 here placed in the Globorotaliidae) ; the recognition of 

 three new subfamilies in the Hantkeninidae — the 

 Planomalininae, Hastigerininae and Cassigerinellinae — 

 the family being enlarged to include all planispiral 

 planktonic genera with equatorial apertures and thus 

 including some forms placed by Cushman and others 

 in the Globigerinidae; the suppression of two subfami- 

 lies of the Orbulinidae— the Candeininae and PuUenia- 

 tininae — their type genera being placed in other previ- 

 ously described subfamihes; and the naming of the new 

 subfamily Catapsydracinae for the orbulinids with 

 apertural covers. 



Systematic Descriptions 



Family Hantkeninidae Cushman, 1927 



Type genus: Hantkenina Cushman, 1924. 



CoUing of test trochospiral or planispiral or enrolled 

 biserial; chambers spherical, ovate, elongate, clavate or 

 tubulospinate; wall calcareous, perforate, radial in struc- 

 ture; primary aperture symmetrical and equatorial, 

 paired or multiple, may have relict or area! secondary 

 apertures. 



Planomalininae Bolli, Loeblich, and Tappan, 

 new subfamily 



Type genus: Planomalina Loeblich and Tappan, 

 1946. 



Coiling planispiral; chambers spherical, ovate, cla- 

 vate or angular rhomboid; primary aperture equatorial 

 or symmetrically paired, with umbilical portions of 

 successive apertures remaining as relict secondary 

 apertures. 



Range: Cretaceous. 



Genus Clobigerinelloides Cushman and ten Dam, 1948 



Plate 1, Figures la, b 



Globigerinelloides Cushman and ten Dam, Contr. Cushman Lab- 

 Foram. Res., vol. 24, p. 42, 1948. 



Type species: Globigerinelloides algeriana Cushman 

 and ten Dam, 1948. Fixed by original designation and 

 monotypy. 



Test free, planispiral, evolute to nearly involute, 

 biumbilicate ; early chambers subglobular, later cham- 

 bers ovate and flaring out in a more evolute coil, with a 

 flange extending on each side back to the previous 

 whorl, somewhat curved backward at the umbilical 

 margin; sutures distinct, depressed, radial in the early 

 coil, later sigmoid; wall calcareous, finely perforate, 

 radial in structure, surface smooth or roughened; 

 aperture interiomarginal, an equatorial arch. 



Remarks: Globigerinelloides resembles Hastigerina 

 Thomson in being planispiral with an equatorial aper- 

 ture, but in Globigerinelloides the later chambers have 



