Phylum Protoplasta [ 185 



Family 3. Spirillinidea Reuss 1861. Family Spirillinina Lankester (1885). Family 

 Silicinidae Cushman. In Spirillina, the perforate hyaline one-chambered shell is 

 planispirally coiled; the family is distinguished by a shell of this form in the young 

 stages if not throughout life. Silicina is a Jurassic fossil whose shell is silicified. In 

 Patellina the spirally coiled first chamber is followed by others arranged in a heHx. 



Family 4. Ammodiscida [Ammodiscidae] Rhumbler 1895. Like the preceding 

 family, but the shell consisting of agglutinated foreign matter. Ammodiscus etc. 



Order 2. Miliolidea Lankester in Enc. Brit. ed. 9, 19: 846 (1885). 

 Order Flexostylida Calkins Biol. Prot. 355 (1926). 



Rhizopoda with imperforate porcellanous shells, a numerous and important group. 



Family 1. Miliolida [Miliolidae] d'Orbigny (1839). Families N uhecularina, Milio- 

 lina, and Hauerinina Lankester (1885). Fisherinidae Cushman. The genus Cornu- 

 spira, known from the carboniferous, differs from Spirillina only in the texture. Evi- 

 dently evolved from this are genera of planispirally coiled tubes divided into chambers, 

 and from these others in which the series of chambers becomes straight or irregular, 

 as in Vertebralina and Tubinella. There is an important block of genera in which each 

 cycle of chambers is of two members, the second opening at the opposite end of the 

 body from the first. In O phthalmidium and Pyrgo alternate chambers lie regularly 

 on opposite sides of a body whose form is that of an elliptic flake. In other genera 

 of this group successive chambers are not opposite each other, but separated by less 

 than 180°, so that more than two appear on the outside. In Triloculina three cham- 

 bers are externally visible. In Miliola Lamarck [Miliolina Lamarck, the latter name 

 applied to fossil representatives of the same genus) the chambers are 144° apart, so 

 that five appear on the outside. In many members of the family the apertures are 

 partially blocked by teeth, single, double, or multiple, or extended as bars clear across. 



Family 2. Soritina Ehrenberg (1839). Family Helicosorina Ehrenberg op. cit. 

 Family Peneroplidea Reuss 1861. Family Peneroplidina Lankester (1885). Family 

 Peneroplidae Cushman. Family Soritidae Galloway (1933). Specialized derivatives 

 of the lower Miliolida: planispiral shells in which the chambers become successively 

 larger, as in Peneroplis, and, by a further development, divided into large numbers 

 of secondary chambers, as in Archaias, Sorites, and Orbitolites. Spirolina, the shell 

 coiled in the oldest part, straight in the remainder. 



Family 3. Alveolinea Ehrenberg (1839). Family Alveolinida Schultze 1854. 

 Families Alveolinina and Keramosphaerina Lankester, Alveolinellidae and Keramo- 

 sphaeridae Cushman. Another group of specialized derivatives, the planispirally coil- 

 ing chambers broadened and divided into many chamberlets with separate apertures, 

 the entire body more or less globular. Borelis; Fasciolites Parkinson 1811 [Alveo- 

 lina d'Orbigny 1826); Alveolinella; Keramosphaera Brody, a rare antarctic form. 

 The organisms of these last two families resemble, as a parallel development, those 

 of order Nummulitinidea, from which they are distinguished by the texture. 



Order 3. Foraminifera Zborewski 1834. 



Order Polythalamia and subordinate group Polysomatia Ehrenberg in Abh. 



Akad. Wiss. Berlin (1838): table 1 (1839). 

 Order Polysomatia Siebold in Siebold and Stannius Lehrb. vergl. Anat. 1 : 11 



(1848). 

 Orders Lituolidea, Textularidea, and Lagenidea Lankester in Enc. Brit. ed. 9, 



19: 847 (1885). 



