18 



PROTOZOA 



Orbiculina, Lamarck ; Orbitolites, Lamarck (by a division of the 

 chambers regularly into chamberlets, and a cyclical mode of growth 

 which results in shells of the size of a shilling, a very elaborate- 

 looking structure is produced which has been admirably analysed 

 by Carpenter (40), to whose memoir the reader is specially referred). 



FIO. XI.MilioKna (Triloculina) tenera. Young living animal with ex- 

 panded pseudopoJia (after Max Schultze). A single nucleus is seen ill the 

 innermost chamber. 



Fam. 5. ALVEOLININA. Shell spiral, elongated in the line of 

 the axis of the convolution ; chambers divided into chamberlets. 

 Genxis. Alreolina, D'Orb. 



Fam. 6. KERAMOSPHJERINA. Shell spherical ; chambers in con- 

 centric layers. 



Genus. Keramosphaera, Brady. 



ORDER 4. LITUOLIDEA, Brady. 



Characters. Test arenaceous, usually regular in contour ; septa- 

 tion of the many-chambered forms often imperfect, the cavity being 

 labyrinthic. This order consists of sandy isomorphs of the simpler 

 Miliolidea, and also of the simpler Perforata (Lagena, Nodosaria, 

 Cristellaria, Globigerina, Rotalia, Nonionina, &c. ) ; it also contains 

 some peculiar adherent species. 



Fam. 1. LITUOLINA. Test composed of coarse sand-grains, rough 

 externally ; often labyrinthic. 



Genera. Reophax, Montfort ; Haplophragmium, Reuss (Fig. 

 X. 7) ; CosTcinolina, Stache ; Placopsiliiia, D'Orb. ; Haplostiche, 

 Reuss ; Lituola, Lamarck ; Bdclloidina, Carter. 



Fam. 2. TROCHAMMININA. Test thin, composed of minute 

 sand-grains incorporated with calcareous and other organic cement, 

 or embedded in a chitinous membrane ; exterior smooth, often 

 polished ; interior smooth or rarely reticulated ; never labyriuthic. 



Genera. Thurammina, Brady (test consisting typically of a 

 single spherical chamber with several mammillate apertures, Fig. 

 X. 5, 6) ; Hippocrepina, Parker ; Hormosina, Brady ; Ammo- 

 discus, Reuss ; Trochammina, Parker and Jones ; Carterina, 

 Brady; Webbina, D'Orb. 



Fam. 3. ENDOTHYRINA. Test more calcareous and less sandy 

 than in the other groups of Lituolidea ; sometimes perforate ; 

 septation distinct. 



Genera. Nodosinella, Brady ; Polyphragma, Reuss ; Inrolutina, 

 Terij. ; Endothyra, Phillips ; Bradyina, Moll. ; Stachcia, Brady. 



Fam. 4. LOFTUSINA. Test of relatively large size ; lenticular, 

 spherical, or fusiform ; constructed either on a spiral plan or in 

 concentric layers, the chamber cavities occupied to a large extent 

 by the excessive development of the finely arenaceous cancellated 

 walls. 



Genera. Cydammina, Brady ; Loftusia, Brady ; Parkeria, 

 Carpenter. 



SUB-CLASS B. Perforata. 



Characters. Shell substance perforated by numerous minute 

 apertures, through which as well as from the main aperture the 

 protoplasm can issue. 



ORDERS. TEXTULARIDEA, Brady. 



Characters. Tests of the larger species arenaceous, either with 

 or without a perforate calcareous basis ; smaller forms hyaline and 

 conspicuously perforated. Chambers arranged in two or more 

 alternating series, or spiral or confused ; often dimorphous. 



Fam. 1. TEXTL-LAUINA. Typically bi- or tri-serial ; often bi- 

 rarely tri-morphous. 



Genera. Texlularia Defrance ; Cuneolina, D'Orb. ; Verneiul- 

 ina, D'Orb. ; Tritaxia, Reuss ; Chrysalidina, D'Orb. ; Bigenerma, 

 D'Orb.; Pawnina, D'Orb.; Spiroplecta, Ehr. ; Gaudryina, D'Orb.; 

 Valvulina, D'Orb.; Clamdina, D'Orb. 



Fam. 2. BULIMININA. Typically spiral ; weaker forms more 01 

 less regularly biserial ; aperture oblique, comma-shaped or some 

 modification of that form. 



Genera. Bulimina, D'Orb. ; Virgulina, D'Orb. ; Bifarina, 

 Parker and Jones ; Bolivina, D'Orb. ; Plcurostomella, Reuss. 



Fam. 3. CASSIDULINA. Test consisting of a Textularia-like series 

 of alternating segments more or less coiled upon itself. 



Genera. Cassidulina, D'Orb.; Ehrenbcrgina, Reuss. 



ORDER 6. CHILOSTOMELLIDEA, Brady. 



Characters. Test calcareous, finely perforate, many-chambered. 

 Segments following each other from the same end of the long axis, 

 or alternately at the two ends, or in cycles of three, more or less 

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

 segment. 



Genera. EllipsoiduM, Seguenza; Chilostomclla, Reuss; Allo- 

 morphiiia, Reuss. 



ORDER?. LAGENIDEA, Brady. 



Characters. Test calcareous, very finely perforated ; either 

 single-chambered, or consisting of a number of chambers joined in 

 a straight, curved, spiral, alternating, or (rarely) branching series. 

 Aperture simple or radiate, terminal. No interseptal skeleton nor 

 canal system. 



Fam. 1. LAGENINA. Shell single-chambered. 



Genera. Lagena, Walker and Boys; Nodosaria, Lamk. ; Lin- 

 gulina, D'Orb. ; Frondicularia, Defrance ; Rhabdogonium, Reuss ; 

 Marginulina, D'Orb. ; Vaginulina, D'Orb. ; Bimulina, D'Orb. ; 

 Cristellaria, Lamk. ; Amphicoryne, ScUumb. ; Lina / ulinopsis,'Re\iss; 

 Flabellina, D'Orb. ; Amphimorphina, Neugeb. ; Dentalinopsis, 

 Reuss. 



Fam. 2. POLYMORPHININA. Segments arranged spirally or 

 irregularly around the long axis ; rarely biserial and alternate. 



Genera. Polymorphina, D'Orb. ; Dimorphiiia, D'Orb. ; Uviger- 

 ina, D'Orb. ; Sagrina, P. and J. 



Fam. 3. RAMULININA. Shell branching, composed of spherical 

 or pyriform chambers connected by long stoloniferous tubes. 



Genus. Ramulina, Rupert Jones. 



ORDER 8. GLOBIGERINIDEA, Brady. 



Characters. Test free, calcareous, perforate ; chambers few, 

 inflated, arranged spirally ; aperture single or multiple, con- 

 spicuous. No supplementary skeleton nor canal system. All the 

 larger species pelagic in habit. 



Genera. Globigerina, D'Orb. (Fig. XII. 6) : Orbulina, D'Orb 

 (Fig. XII. 8) ; Hastigerina, Wy. Thomson (Fig. XII. 5) ; Pul- 

 Unia, P. and J. ; Sphxroidina, D'Orb. ; Candeina, D'Orb. 



ORDER 9. ROTALIDEA, Brady. 



Characters. Test calcareous, perforate ; free or adherent. Typi- 

 cally spiral and "rotaliform" (Fig. XII. 2), that is to say, coiled 

 in such a manner that the whole of the segments are visible on the 

 superior surface, those of the last convolution only on the Inferior 

 or apertural side, sometimes one face being more convex sometimes 

 the other. Aberrant forms evolute, outspread, acervuline, or 

 irregular. Some of the higher modifications with double chamber- 

 walls, supplemental skeleton, and a system of canals. The nature 

 of this supplemental skeleton is shown in Fig. XII. 2 and 10. 



Fam. 1. SPIRILLINIXA. Test a complanate, plauospiral, non- 

 septate tube ; free or attached. 



Genus. Spirillina, Ehr. 



Fam. 2. ROTALINA. Test spiral, rotaliform, rarely evolute, very 

 rarely irregular or acervuline. 



Genera. Patcllina, Williamson ; Cymbalopora, Hay ; Discorbina, 

 P. and J. ; Planorbulina, D'Orb. ; Truncatulina, D'Orb. ; Anomal- 

 ina, P. and J. ; Carpentaria, Gray (adherent) ; Rupcrtia, 

 Wallick ; Pulvinulina, P. and J. ; Rotalia, Lamk. ; Calcarina, 

 D'Orb. [Shell rotaliform ; periphery furnished with radiating 

 spines ; supplemental skeleton and canal system largely developed. 

 This form is shown in a dissected condition in Fig. XII. 10. Outside 

 and between the successive chambers with finely perforated walls 

 a 2 , a 3 , a* a secondary shell-substance is deposited by the proto- 

 plasm which has a different structure. Whilst the successive 

 chambers with their finely perforate walls (resembling dentine in 

 structure) are formed by the mass of protoplasm issuing from the 

 mouth of the last-formed chamber, the secondary or supplemental- 

 shell substance is formed by the protoplasm which issues through 

 the fine perforations of the primary shell substance ; it is not 

 finely canaliculated, but is of denser substance than the primary 

 shell and traversed by coarse canals (occupied by the protoplasm) 

 which make their way to the surface of the test (c' t c"). In Cal- 

 carina a large bulk of this secondary shell-substance is deposited 

 around each chamber and also forms the heavy club-like spines.] 



Fam. 3. TINOPORINA. Test consisting of irregularly heaped 

 chambers with (or sometimes without) a more or less distinctly 

 spiral primordial portion ; for the most part without any general 

 pseudopodial aperture. 



