34 PROTOZOA—RHIZOPODA CLASS I 
cesses. The ramifications of these lateral processes (fi/et cloisonnaire) may be 
readily seen on fracturing a portion of the test, and are a 
valuable aid in the determination of species. The oldest 
Nummulites (1. pristinus, Brady) occur very sparsely in the 
Carboniferous Limestone and Upper Jurassic, but are dis- 
tinguished from the typical later forms by the absence of 
an interior canal-system in the marginal cord. The typical 
SP] Nummulites which are so characteristic of the Eocene (Num- 
Fic. 41. mulitic limestone) in Europe, North Africa, Asia, and Central 
“ Nummutites (Assi- America, often build up massive formations. The largest 
re eens EO" snecies (N. Gizehensis, Ehrbg., N. orbiculatus, Schafh.) attain 
a diameter of 60 mm.; the smallest species does not exceed 
2 mm. ; recent representatives comparatively scarce. 
Polystomella, VOrb. (Fig. 44); Nonionina, dOrb.; Cycloclypeus, Carp. 
Tertiary and Recent. 

Al 

C3 G12 Fic. 42. Bl 
A, Nummulites Gizehensis, Ehrbg. Eocene; Libyan Desert. Natural size. 43, Specimen with eroded peri- 
pheral portion, showing arrangement of septa. B12, Nummulites laevigatus, Lam. Calcaire Grossier; Paris. 
Natural size. B#, Portion of same enlarged. C12, Nummulites Ramondi, Defr. Eocene (Nummulitic lime- 
stone); Pyrenees. Natural size. C%, Enlarged section. 
Orbitoides, @Orb. (Hymenocyclus, Bronn ; Lycophrys, Montf.), (Fig. 45). Test 
discoidal, with circular or stellate contour, often bent, exterior smooth or with 

A, Nuniunulitie limestone with horizontal sections of Fia. 44 
N. distans, Pusch. Peyrehorade, in the Pyrenees. JB, Polystomella crispa, Lam. 
Numiulitic limestone showing sections of N. Lucasanus, Pliocene ; Sienna, Italy. 
Defr. Zakophane in the Carpathians. (Highly magnified.) 
radial striae, and composed of numerous concentric annuli disposed about a 
