310 FORAMINIFERA 



Subfamily 4. Candeininae 



Test trochoid, in the young with the chambers roughened and 

 spinose and with the aperture single as in Globigerina, in the 

 adult the chambers smooth, without spines and the apertures 

 formed by rows of circular or elliptical openings along the 

 sutures. 



Genus CANDEINA d'Orbigny, 1839 



Plate 47, figures 18-21 ; plate 48, figure 3 

 Genoholotype, Cavdehia nitkla d'Orbigny 

 Candeina d'Orbigny, in De la Sagra, Hist. Fis. Pol. Nat. Cuba, 1839, 

 "Foraminiferes", p. 107. 



Test trochoid, in the young with the chambers somewhat 

 roughened and spinose and with the aperture as in Globigerina, 

 in the adult the chambers smooth, without spines, and the aper- 

 tures consisting of rows of circular openings along the sutures. 



Late Tertiary and Recent. 



The Globigerinidae represent the most successful adaptation 

 of the f oraminif era to pelagic life. The family developed strong- 

 ly in the Cretaceous where it dominated certain of the environ- 

 mental conditions at that time with the Globorotaliidae. This 

 relationship still prevails and the two groups today form the 

 great mass of the pelagic foraminifera, and are the main con- 

 stituents of Globigerina-ooze which covers immense areas of the 

 ocean bottom. In the late Tertiary the more specialized forms 

 of Orbulina, Candeina, Hastigerina, Pulleyiiatiyia and Sphaeroidin- 

 ella developed. In Orbulina, there is the perfect adaptation to 

 pelagic life. 



This family has developed from the umbilicate Rotaliidae 

 such as Discorbis, and the young of all the species of Globigerina 

 in the microspheric form are smooth, flattened forms very sim- 

 ilar to Discorbis. The globular form of the chambers is attained 

 later. The reversion to this condition seen in the development 

 of their own young takes place in the next family. The develop- 

 ment of a thick surface clothing of fine spines is unique in this 

 family and is developed with their adaptation to pelagic life. The 

 peculiar plate-like structure that develops over the umbilical 

 area in fossil forms and which is occasionally seen in recent 

 ones is foreshadowed in the similar structure developed in 



