FORAMINIFERA. 11 



SUB-CLASS FORAMINIFERA. 



Microscopic animals ; not aggregated ; of gluti- 

 nous consistence; rounded, or divided into seg- 

 ments, placed in a line, or rolled spirally ; enveloped 

 in a shell, which is modelled on the form of the 

 body ; giving off, through orifices in the shell, soft 

 filaments, which are contractile, colourless, very 

 long, branched, and used for locomotion. 



Body composed of one segment ; shell of 

 one chamber Monostegia. 



Body of segments placed in one line ; shell 

 of chambers built up end to end in a straight 

 or curved line Stichostegia. 



Body of segments rolled in a spiral ; cham- 

 bers of shell piled on one axis, in a spiral . Helicostegia. 



Body of alternate segments forming a 

 spiral; shell-chambers piled on two axes, 

 alternating, and rolled in a spiral Entomostegia. 



Body of alternate segments crowded to- 

 gether, not in a spiral : chambers alternate, 

 crowded, on two or three axes, not forming 

 a spiral Enallostegia. 



Body of segments twined (par pelotonnement) 

 round an axis ; chambers similar, each making 

 a half-circumvolution Agathistegia. 



Order I. MONOSTEGIA. 



Lagena (Walker). Cell calcareous, single, glo- 

 bular, ovate, or cylindrical, with a long external 

 tubular neck projecting from the upper extremity. 



L. laevis. L. striata. Fig. 9 ; mag. 9 -f 



gracilis. substriata. 



Entosolenia (Ehrenberg). As Lagena, but the 

 tube projects downwards into the cavity of the 

 cell. 



E. globosa. E. lineata. 



squamosa. marginata. Fig. 10. section ; --&. 



