JONES AND PARKER FORAMINIFERA OF LONDON CLAY. 87 
Sow., iV^. affinis, D'Orb., etc. Common in the London Clay, the 
Vienna basin, the subapenniiie Tertiaries, the Malaga, San Domingo, 
and other clays, and recent at Jamaica. 
Fig. 10. Nodosaria Raphanus, Linn. This is less developed com- 
pared with the foregoing, and is equally, if not more abundant in the 
recent and fossil state. Its modifications are endless, and its names 
proportionally numerous. There is no real demarcation either between 
N. Raphanus aud N. Raphanistrum, or between them and their sub- 
varieties, however modified as to size and number of riblets, close- 
ness or division of the chambers, conicity or cylindricity of the shell, 
its straightness or curvature, or the more or less central position of 
the aperture. Gradual changes lead us, on one hand, to the costu- 
late and prickled Dentalinae aud Marginulinae above referred to ; and, 
on the other, to the smooth Nodosaria radicula and Dentalina com- 
munis ; whilst Yaginulinae, Marginulinje, and Cristellariae, with and 
without riblets, come out, as it were, from the straighter forms with- 
out any real specific differences, however convenient it may be to 
retain distinct names for nearly all the modifications alluded to. 
Fig. 12. Marginulina Wetherellii, Jones, in Morris's Catal. Brit. 
Foss. 1854, p. 37. Montagu had this little shell also in the Boysian 
Collection, doubtlessly from the clifi-washings of Kent, and referred it, 
erroneously, to what is now known as a narrow variety of Penei^oplis 
planatus. It is one of the most common of the Foraminifera of the 
London Clay, and though somewhat similar Marginulinae occur in 
other Tertiary beds (San Domingo), and even in the Chalk (of Meck- 
lenburg),* and the Clays of the Oolites, yet it remains as a distinct 
variety. It had a peculiar habit of ending its growth with one or 
more simple, contracted, smooth, dentaline chambers, figured both by 
Montagu and Sowerby. 
Fig. 13. Cristellaria cultrata, Montfort. A common, nautiloid, 
keeled Cristellaria, common in many deposits, both of Secondary and 
Tertiary age, and abundant in the living state in the existing seas at 
many places. AVhen the keel is wanting, we have C. rotulata, La- 
marck ; when the shell is large-keeled and rowelled, it is Q. Galcar^ 
Linn. ; when flattened and broad, it is C. Cassis, Fichtel and Moll. 
Figs. 14-18. These little Rotaline shells are small varieties of 
Flanorbulina farcta, Fichtel and Moll (Ann. Nat. Hist. 3 ser. vol. v. 
p. 177, etc.). They range between the varieties figured and described 
by D'Orbigny as Rotalia Haidingeri and R. Ungeriana ; and Eeuss's 
R. ammonoides, D'Orbigny' s R. Akneriana and R. Duiemplei, are 
scarcely, if at all, divisible from R. Ungeriana. All of these abound 
in the present oceans. Another neitr modification of this form is 
shown in the well-known Planorhulina (Truncatulina) lohatula, 
Walker and Jacob, which also occurs in the London Clay, though 
not so plentifully as the foregoing, and frequents shallower water 
than they do. 
* Cristellaria decorata, Reuss, Zeitsch. d. g. Ges. vii. pi. viii. fig. 66, and pi. xix. 
tigs. 1, 2. .... 
