FORAMINIFERA. 895 



ktthnia,) Microgromia, Grotnia, Diaphoropodon ; with an aperture at each end of the 

 test, Shepheardella. 



Fam. 2. Miliolidae. Test imperforate, normally calcareous and porcellanous, 

 sometimes encrusted with sand ; under starved conditions (e. g. in brackish water) 

 becoming chitinous or chitino-arenaceous ; at abyssal depths occasionally consist- 

 ing of a thin homogeneous siliceous film ; contains Nubecularinae ; Miliolininae ; 

 Hauerininae ; Peneroplidinae, e. g. Cornuspira, Peneroplis^ Orbitolites ; Alveolininae ; 

 Keramosphaerinae. 



Fam. 3. Astrorhizidae. Test invariably composite, usually of large size and 

 monothalamous ; often branched or radiate, sometimes segmented by constriction 

 of the walls, but seldom or never truly septate ; polythalamous forms never sym- 

 metrical ; contains Astrorhizinae with thick walls to test composed of loose sand, or 

 mud, slightly cemented, e. g. Astrorhiza, Pelosina^ Syringammina ; Pilulininae with 

 monothalamous test, composed of loosely felted sponge-spicules and fine sand 

 without any cement, Pilulina^ Technitella, B athy siphon ; Saccamininae with thin 

 spherical chambers composed of firmly cemented sand-grains, Psammosphaera, 

 Sorosphaera, Saccamina ; Rhabdamminae, test composed of firmly cemented sand- 

 grains often with sponge-spicules intermixed ; tubular, straight, radiate, branched or 

 irregular ; free or adherent ; with one, two, or more apertures ; rarely segmented, 

 e. g. Jaculella, Marsipella^ Rhizammina, Sagenella, Haliphysema. 



Fam. 4. Lituolidae. Test arenaceous, usually regular in contour ; septation of 

 polythalamous forms often imperfect ; chambers frequently labyrinthic. Comprises 

 sandy isomorphs of the simple .porcellanous and hyaline types together with some 

 adherent species ; contains Lituolinae ; Trochammininae ; Endothyrinae (extinct) ; 

 Loftusinae Cydammina, Loftusia^ Parkeria. 



Fam. 5. Textularidae, Tests of the larger species arenaceous, either with or 

 without a perforate calcareous basis ; smaller forms calcareous and conspicuously 

 perforate. Chambers arranged in two or more alternating series, in a spiral, or con- 

 fused ; often dimorphous ; contains Textularinae ; Bulimininae ; Cassidulininae. 



Fam. 6. Chilostomellidae. Test calcareous, finely perforate, calcareous. Seg- 

 ments following each other from the same end of the long axis (Ellipsoidina) or 

 alternately at the two ends {Chilostomelld), or in cycles of three (Allomorphina\ 

 more or less embracing. Aperture a curved slit at the end or margin of the final 

 segment. See note i, p. 886. 



Fam. 7. Lagenidae. Test calcareous, very finely perforated; either mono- 

 thalamous, or consisting of a number of chambers joined in a straight, curved, 

 spiral, alternating or rarely branching, series. Aperture simple or radiate, terminal. 

 No supplemental skeleton nor canal system ; contains Lageninae ; Nodosarinae ; 

 Polymorphininae ; Ramulininae. 



Fam. 8. Globigerinidae. Test free, calcareous, perforate; chambers few, 

 inflated, arranged spirally ; aperture single or multiple, conspicuous. No supple- 

 mental skeleton nor canal system. All the larger species pelagic in habitat ; e. g. 

 Globigerina, Orbulina, Hastigerina. 



Fam. 9. Rotalidae. Test calcareous, perforate, free or adherent. Typically 

 spiral and ' Rotaliform,' i. e. coiled so that the whole of the segments are visible on 

 the superior surface, those only of the last convolution on the inferior or apertural 

 side, sometimes one face being more convex, sometimes the other. Aberrant forms 

 evolute, outspread, acervuline (i. e. irregularly massed) or, irregular. Some of the 



