SPECIAL MORPHOLOGY AND TAXONOMY OF SARCODINA 355 



Family 2. Ammodisculinidse, Rhiimbler.— In part sand in part 



lime shells of tubular, discoid or rolled form, imperforate or perforate. 



Genera: A. Imperforate sand shells. Genus G'm'a7?f//cr, Nich. 



and Eth.; Liiuohiha, Rhumbler; Fsammonyx, Doderlein; 



Ammonodisctis , Reuss.; B. Imperforate lime shells. Cor- 



nuspira, M. Schultze; C. Perforate lime shells, with 



chamber-like swellings and incomplete septa. 



Genera: SpiriUina, Bory; Tetrataxis, Ehren.; Patellina, 



Williamson. 



Order II. Nodosalida = Nodosalidia, Rhumbler. 



Shells usually chambered but monothalamous forms may arise 

 by separation of newly-formed chambers. Chambers in straight 

 or slightly curved rows, occasionally in a flat spiral row (Cristel- 

 laria) ; initial chamber without a bent neck. 



Family 3. Nodosamminidae, Rhumbler.— Shells sandy or more or 

 less calcareous ; perforate or imperforate; invariably poly thalamous; 

 chambers in a straight or slightly bent row. 



Genera: Nodosinella, Brady; Fheojjhax, Montf. 

 Family 4. Nodosariidse, Rhumbler. — Shells pure limestone with 

 many fine and closely set perforations. 



Genera: Nadosaria, Lamarck; Vaginulina, Eornas; Lagena, 

 Walker and Boys; Cristellaria, Link. 



Order III. Flexostylida = Flexostylidia, Rhumbler. 



The globular initial chamber is provided with a flexible, sac-like 

 or tubular "neck" which winds around the original chamber and 

 becomes attached to the second chamber. Walls usually imper- 

 forate or with sparse perforations; shells usually calcareous, por- 

 cellanous and not infrequently mixed with sand. In brackish 

 water shells pseudochitinous or with sand cr^'stals, in deep sea also, 

 but exceptionally silicious. 



Family 5. Miliolinidse, Brady em. Rhumbler.— Shells spirally 

 wound without cyclical growth; imperforate except for the initial 

 chamber of Peneroplis which is perforate. 



Genera: Group A: Chambers long, usually including one-half 

 a spiral turn. Nodobecvlaria, Rhumbler; Nuhecularia, 

 Defr.; Calcituha, Roboz; Biloculina, d'Orb.; Miliolina, 

 Williamson; Triloculina, D'Orb; Quinquelorulina, d'Orb.; 

 Ojjhthcilmidiinn, Kubl. and Zwingli; Spiroloculina, d'Orb. 

 Group B: Chambers very short so that many are included 

 in one turn, but occasionally very wide; Peneroplis, Montf. ; 

 Alvenlina, d'Orb. 

 Family 0. Orbitolinidse, Reuss em. Rhumbler. — In the later rows 

 chamber growth becomes cyclical or ring form, with division of 



