FORAMINIFERA 399 



Genus Lituola Lamarck (Fig. 186, a) 



Axis of coil usually long, all close-coiled 



Interior not labyrinthic; fossil only Family 9 Fusulinidae 



Genus Fusulina Fisher (Fig. 186, b) 

 Interior labyrinthic; fossil only Family 10 Loftusiidae 



Genus Loftusia Brady 



Test typically biserial at least in young of microspheric form; fossil 

 and recent Family 11 Textulariidae 



Fig. 186. a, Lituola nautiloidea (Cushman); b, section through a 

 Fusulina (Carpenter); c. Textularia agglutinans, X90 (Rhumbler); d. 

 Verneuilina propinqua, X8 (Brady); e, Valvulina triangularis, (d'Or- 

 bigny); f, Trochammina inflata, X32 (Brady); g, Placopsilina cenomana 

 (Reuss); h, Tetrataxis palaeotrochus, Xl5 (Brady); i, Spirolocvlina 

 limbata, X20 (Brady); j, Triloculina trigonula, X 15 (Brady); k, Fischer- 

 ina helix, X32 (Heron-Allen and Earland); 1, Vertebralina striata, X40 

 (Kiihn); m, Alveolinella mello, X35 (Brady). 



Genus Textularia Def ranee (Fig. 186, c) 



Test typically triserial at least in young of microspheric form 



Aperture usually without a tooth, test becoming simpler in higher 

 forms; fossil and recent Family 12 Verneuilinidae 



Genus Verneuilina d'Orbigny (Fig. 186, d) 



Aperture typically with a tooth, test becoming conical in higher 

 forms; fossil and recent Family 13 Valvulinidae 



