THE FORAMINIFERA 145 



entirely (Fig. 47). Amphicoryne, Schlumb. Early chambers cristellarian, 

 later nodosarian. Allied are the fossil biformed genera Lingulinopis, Reuss ; 

 Flabellina, d'Orb. ; Amphimorphina, Neugeb. ; and Dentalinopsis, Reuss. 



FAMILY 3. POLYMORPHINIDAE. Chambers arranged spirally or 

 irregularly round the long axis, rarely biserial or alternate. Genera 

 Polymorphina, d'Orb. Bi- or tri-serial, or irregularly spiral, aperture 

 radiate (Fig. 48). Dimorphina, d'Orb. Early chambers polymorphine, 

 later nodosarian. Uvigerina, d'Orb. More or less spiral, aperture pro- 

 duced, often tubular, and lipped. Sagrina, P. and J. Early chambers 

 uvigerine, later nodosarian. 



FAMILY 4. RAMULINIDAE. Test irregular, branching. Genus Ramu- 

 lina, R. Jones. 



ORDER 8. Globigerinidea. 



Test free, calcareous, perforate ; chambers few, inflated, arranged 

 spirally ; aperture single or multiple, conspicuous. No canalicular 

 skeleton or canal-system. All the larger species pelagic in habit. Genera 

 Globigerina, d'Orb. Test coarsely perforated, trochoid, rotaliform or 

 symmetrically piano-spiral, pelagic specimens usually spinous (Fig. 49). 

 Orbulina, d'Orb. A spherical test with large and small perforations, beset 

 with spines, and containing a Globigerina-shell. It is a late phase in 

 the life-history of some forms at any rate, of Globigerina (Fig. 49). 

 Hastigerina, Wy. Th. Regularly nautiloid and involute, armed with 

 long serrate spines, which are triangular in section, aperture large. 

 Pullenia, P. and J. Regularly or obliquely nautiloid and involute, 

 chambers only slightly ventricose, aperture a long curved slit, pores very 

 minute. Sphaeroidina, d'Orb. Chambers forming together a nearly 

 globular shell. Candeina, d'Orb. Trochoid, thin -walled, aperture con- 

 sisting of rows of pores. 



ORDER 9. Rotalidea. 



Test calcareous, perforate ; free or adherent ; typically spiral and 

 "rotaliform," i.e. coiled so that all the chambers are visible on the 

 " superior," " dorsal," or " apical " side, those of the last convolution only 

 on the " inferior," " basal," or " apertural side," sometimes one side being 

 convex, sometimes the other. Aberrant forms evolute, outspread, acervu- 

 line, or irregular. Some of the higher modifications with double 

 chamber-walls and canalicular skeleton. 



FAMILY 1. SPIRILLINIDAE. Test spiral, non- septate. Genus 

 Spirillina, Ehrbg. Complanate and piano-spiral, free or attached. 



FAMILY 2. ROTALIDAE. Test rotaliform, rarely evolute, very rarely 

 irregular or acervuline. Genera Patellina, Will. Test conical, with an 

 external layer of spirally arranged or annular chambers, subdivided into 

 chamberlets, the interior of the cone filled either with hyaline shell-sub- 

 stance, or with chambers. Cymbalopora, Hag. More or less trochoid. 

 Early chambers spiral, later concentric, pelagic specimens with a large in- 

 flated chamber covering the base of the shelL Discorbina, P. and J. Free 

 or adherent, rotaliform, trochoid or plano-convex, with either the superior 

 or the inferior (apertural) surface convex, somewhat coarsely porous, 



10 



