142 THE FORAMINIFERA 



ORDER 3. Lituolidea. 



Test arenaceous, usually regular in contour, chambers of the poly- 

 thalamous forms frequently labyrinthic. Comprises sandy isomorphs of 

 the simple porcellanous and hyaline types (Cornuspira, Peneroplis, Lagena, 

 Nodosaria, Cristellaria, Globigerina, Rotalia, Nonionina, etc.), together 

 with some adherent species. 



FAMILY 1. LITUOLIDAE. Test of coarse sand grains, rough ex- 

 ternally ; often labyrinthic. (a) Chambers non-labyrinthic. Genera 

 Reophax, Montf. Test free, composed of one flask-shaped chamber, or of 

 several united into a straight, curved, or irregular line, never spiral. 

 Coskinolina, Stache ; Haplophragmium, Reuss. Test free, nautiloid, or 

 crosier-shaped. Placopvilina, d'Orb. Chambers plano-convex, adherent. 

 (6) Chambers labyrinthic. Genera Haplostiche, Reuss. Test free, uni- 

 serial, never spiral. Lituola, Lamk. Test free, nautiloid, or crosier-shaped. 

 Bdelloidina, Carter. Adherent. 



FAMILY 2. TROCHAMMINIDAE. Test thin, composed of minute sand 

 grains incorporated with calcareous or other cement ; smooth, often 

 polished externally. Genera Thurammina, Brady. Test a single sub- 

 spherical chamber. Hippocrepindj Parker ; Hormosina, Brady. A 

 rounded chamber, or several in a straight or curved series. Ammodiscu$, 

 Reuss. Test non-septate, coiled in a piano-spiral (resembling Spirillina) 

 or otherwise. Trochammina, P. and J. Free or adherent, rotaliform, 

 nautiloid or trochoid. Carterina, Brady. Test rotaliform, constructed 

 of fusiform spicules, said to be proper to itself. Webbina, d'Orb. One or 

 more adherent, stoloniferous chambers. 



FAMILY 3. ENDOTHYRIDAE. Fossils. Test more calcareous and 

 less sandy than in other Lituolidae, sometimes perforate. Genera 

 Nodosinella, Brady. Nodosariform. Polyphragma, Reuss. Involutina, 

 Terq. Endothyra, Phil. Bradyina, Moll. Stacheia, Brady. 



FAMILY 4. LOFTDSIIDAE. Test relatively large, lenticular, spheri- 

 cal or fusiform ; arranged spirally, or in concentric layers ; walls finely 

 arenaceous and cancellated. Genera Cyclammina, Brady. Nautiloid. 

 Loftusia, Brady. Large, resembling Alveolina in contour. Parkeria, 

 Carp. Large, spheroidal 



ORDER 4. Miliolidea. 



Test usually imperforate, normally calcareous and porcellanous, some- 

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

 becoming chitinous or chitino-arenaceous ; at abyssal depths occasionally 

 consisting of a thin, homogeneous, imperforate, siliceous film. 



FAMILY 1. MILIOLINIDAE. Test of one or many chambers spirally 

 arranged ; in the many - chambered forms there are usually not more 

 than two chambers in each convolution, (a) Test unsegmented, plano- 

 spiraL Genus Cornuspira, M. Sch. (Fig. 20). (6) Test piano-spiral, two 

 chambers to a convolution. Genera Spiroloculina, d'Orb. (Fig. 21). 

 All the chambers exposed on the contour. Biloculina, d'Orb. (Figs. 22, a, 

 and 24). Chambers simple, only the last two chambers exposed on the 



