48 CLASS I. 



A. Body simple (Monostegia D'ORB.) 



* Lorica membranous or horny. 



Arcella EHRENB. Lorica scutellate, globose, or hemispherical, 

 sometimes angulate, open beneath : the animal emitting processes 

 variable, plane, obtuse, through the aperture. 



These animals live in fresh water. See Figures in EHRENBERG'S In- 

 fusionsthierchen, Tab. ix. fig. v vin ; DUJARD, In/us. PL n. fig. 35. 



Difflugia LECLERC. Lorica globose or oval (sometimes sub- 

 spiral?), emitting from the terminal aperture processes of the animal 

 variable, multifidous. 



LECLERC first discovered these forms (1815) ; see Note sur la Difitugie, 

 M 6m. du Museum, II. p. 474 478, PL 17. Bp.Diffl.proteiformis, fig. 2. 3; 

 EHRENB. Infusionsth. Tab. ix. fig. i. The shell, according to LECLERC, 

 is spiral, what later observers did not perceive ; it is covered with minute 

 grains of sand. Diffl. globulosa DUJARDIN, Ann. des Sc. not., ie Serie. 

 Tom. VII. 1837. Zoologie, p. 310, 312. PL ix. fig. i. 



Gromia DUJARD. Lorica globose, membranous, emitting pro- 

 cesses of the animal variable, slender, of great length, from a round 

 aperture. 



Sp. Gromia omformis DUJARD. Ann. des Sc. not. ie Serie, Tom. IV. Zoologie, 

 PL IX. fig. i. 2, in salt water, amongst marine plants ; Gromia fluvia- 

 tilis DUJARD. ibid. Tom. VIII. Zoologie PL 9. fig. 2 ; Grom. oviformis 

 DUJ. SCHULTZE, op. tit. Tab. i. fig. i. 



'* Test calcareous. 

 Genera : Orbulina, Oolina and Amplwrina, D'ORB. 1 



B. Body composed of several segments. Test calcareous, divided 

 by septa into cells. 



* Cells simple, arranged on an axis, straight, or slightly curved. 

 (Stichostegia] . 



Genera : Nodosaria LAM. (Sp. Nodosaria lamellosa D'ORB.) Ann. 

 des Sc. nat. 1826, Tom. vn. Tab. x. fig. 4-6. Glandulina D'ORB. 

 (Sp. Glandul. Icevigata ib. fig. 1-3), Orthocerina, Dentalina D'ORB., 

 Frondicularia DEFR., Lingulina, Rimulina, Vaginulina, Marginu- 

 lina, Conulina, Pavonina, Webbina D'ORB. 



1 Since these small bodies are separated by D'ORBIGNY according to characters 

 especially derived from the shell, we have thought it sufficient, for the sake of brevity, 

 to indicate the names of the genera. 



