FORAMINIFERA 



503 



Genus Cassidulina d'Orbigny (Fig. 213, c) 



With later chambers becoming involute, very few making up the 

 exterior in adult; aperture typically elongate, semicircular; in 



a few species circular; fossil and recent 



Family 37 Chilostomellidae 



Genus Allomorphina Reuss (Fig. 213, d) 



With chambers mostly finely spinose and wall cancellated, adapted, 

 for pelagic life, globular forms with the last chamber com- 

 pletely involute; aperture umbilicate or along the suture; fossil 

 and recent Family 38 Globigerinidae 



Fig. 213. a, Calcarina defrancei, X25 (Brady); b, Halkyardia radiata, 

 Xl5 (Cushman); c, Cassidulina laevigata, X25 (Brady); d, Allomorphina 

 trigona, X40 (Brady); e, Globigerina bxdloides, X30 (Kuhn); f, Anomalina 

 punctulata (d'Orbigny); g, Rupertia stabilis, X50 (Brady). 



Genus Globigerina d'Orbigny (Fig. 213, e) 



Early chambers globigerine, later ones spreading and compressed; 

 fossil and recent Family 39 Globorotaliidae 



Genus Globorotalia Cushman 



Test trochoid at least in young, aperture peripheral or becoming 

 dorsal 

 Mostly attached, dorsal side usually flattened; fossil and recent 

 Family 40 Anomalinidae 



Genus Anomalina d'Orbigny (Fig. 213, /) 



Later chambers in annular series; fossil and recent 



Family 41 Planorbulinidae 



