THE SARCODINA 1 09 



1 



line or irregular. Some of the higher types have double walls, with supple- 

 mental skeleton and a canal system. 



Subfamily i. Spirillince. The shell is a flat spiral, without septa; it may be free 

 or attached. Genera: Spirillina Ehbg ('41). 



Subfamily 2. Rotalince. The shell is spiral, rotaliform, and rarely evolute or ir- 

 regular. Genera : Discorbina Lamarck ('04) ; Planorbulina d'Orb. ('26) ; 

 Truncatulina d'Orb. ('26) ; Anoinalina d'Orb. ('26) ; Rotalia Lamarck (1801) ; 



Calcarina d'Orb. ('26) ; Patellina Williamson ('58) ; Carpenteria Gray ('58) ; 

 etc. 



Suborder 4. TINOPORIN^. The shell consists of irregularly heaped chambers, 

 usually with a more or less spiral primordial portion ; a main pseudopodial 

 aperture is usually absent. Genera: Tinoporus Carpenter ('57); Polytrema 

 Risso ('26) ; Gypsina Carter ; Thalamopora Roemer; Aphrosina Carter. 



Family 10. Nummulinidae. The shell is calcareous and finely tubulated ; it is 

 typically polythalamous, free, and symmetrically spiral. The higher forms pos- 

 sess a supplementary skeleton and a well-developed canal system. 



Subfamily i . FusulinincK. The shell is bilaterally symmetrical, with chambers 

 extending from pole to pole, so that each convolution completely incloses the 

 preceding whorl. The septa between the chambers are single as a rule. Genera: 

 Fusulina Fischer ('29); Schwagerina Moller ('77). 



Subfamily 2. Poly stomelli nee. The shell is bilaterally symmetrical and nautiloid. 

 The simpler forms are without supplemental skeleton ; the more complex forms 

 have a skeleton, and canals leading to the outside at regular intervals along the 

 external septal depressions. Genera : Polystomella Lamarck ('22) ; Nonionina 

 d'Orb. ('26). 



Subfamily 3. Nummulitince. The shell is lens-shaped or flattened. Genera: 

 Archeodiscus Brady ; Amphistegina d'Orb. ('26) ; Operculina d'Orb. ('26) ; 

 Numinulites Lamarck (1801); Heterostegina d'Orb. ('26). 



Subfamily 4. Cycloclypeina. The shell is flat, with a thickened centre, or lens- 

 shaped, and consists of a disc of chambers arranged in concentric annuli with 

 peripheral thickenings. The septa are double, and furnished with a system of 

 interseptal canals. Genera: Cyclodypeus Carpenter ('56) ; Orbitoides d'Orb. 



Subclass II. HELIOZOA. These are naked or shelled forms of Sarcodina of typi- 

 cally spherical form, with but little tendency to change form by amoeboid mo- 

 tion. The pseudopodia, radiating from all parts of the body, are fine and 

 ray-like, rarely changeable, and usually provided with an axial filament. 



Order i. APHROTHORACIDA. Heliozoa, without a skeleton, but provided with a 

 more or less developed power of amoeboid motion, and with plastic (myxopo- 

 dia) or stiff (axopodia) pseudopodia, the latter possessing axial filaments. 

 Genera: Vampyrella Cienk. ('65); Nuclearia Cienk. ('65); Monobia A. 

 Schneider ('78) ; Myxastritm Haeck. ('7) \ Actinophrys Ehr. ('30) ; Actino- 

 spharium Stein ('57) ; Actinolophus F. E. Schultze ('74). 



Order 2. CHLAMYDOPHORIDA. Heliozoa, with a soft gelatinous or felted fibrous 

 covering. Genera: Heterophrys Archer ('69); Sph<zrastrum Greeff ('73); 

 Astrodisculus Greeff ('69). 



Order 3. CHALARATHORACIDA. Heliozoa, with a silicious coating composed of 

 separate and loosely-jointed spicules. Genera: Pompholyxophrys Archer 

 ('69) ; Raphidiophrys Archer ('70) ; Pinacocystis Hert. & Less. ('74) ; Pi- 

 nadophora Greeff ('73) ; Acanthocystis Carter ('63) ; Diplocystis Penard ('90) ; 

 Cienkowskya Schaudinn ; Wagnerella Mereschkowsky ('81). 



Order 4. DESMOTHORACIDA. Heliozoa, with a shell of one piece perforated by 

 numerous openings. Stalked or unstalked forms. Genera: Orbulinella Entz 

 C77) ; Clathrulina Cienk. ('67). 



