170 FORAMINIFERA 



FAMILY 18. FISCHERINIDAE 



Test coiled, earlier ones somewhat planispiral, later ones 

 trochoid, all coils visible from the dorsal side only, the last- 

 formed one from the ventral side; chambers distinct but not 

 inflated, usually four or five making up the last-formed coil; 

 wall calcareous, imperforate; aperture rounded, formed by the 

 open end of the last-formed chamber. 



Genus FISCHERINA Terquem, 1878 

 Plate 20, figures 16-18; plate 21, figure 13 



Genoholotype, Fischerina rhodiensis Terquem 

 Fischerina Tebquem, Mem. Soc. Geol. France, ser. 3, vol. 1, 1878, p. 80. 



Test coiled in a low conical spiral ; chambers few in each coil, 

 all visible from the dorsal side, only those of the last-formed 

 coil from the ventral side; wall calcareous, imperforate; aper- 

 ture formed by the open end of the last-formed chamber, simple. 



Pliocene to Recent, 



This family represented by the single genus Fischerina 

 represents the attempt in fairly recent times of the assuming 

 of a trochoid form. It is surprising that this trochoid form 

 taken on by many groups has never been successfully tried out 

 by the vitreous or porcellanous groups. 



FAMILY 19. TROCHAMMINIDAE 



Test in general trochoid, of numerous chambers, or irregular ; 

 wall arenaceous, with much cement, usually of yellowish- or 

 reddish-brown color, 



KEY TO THE GENERA 



I. Test typically trochoid, not involute. 



A. Test arenaceous. 



1. Without an outer layer Trochammina. 



2. With a distinct outer layer Globivalvulina. 



B. Test of cement with distinct fusiform bodies Carterina. 



C. Test of matted spicules above, chitin below Rotaliammina. 



II. Test irregularly spiral with globose chambers, n«t involute. 



Globotextularia. 



