Sra ae ee ee 
On the Nomenclature of the Foraminifera. 29 
VIII.—On the Nomenclature of the Foraminifera. 
By W. K. Parxer, M. Micr. Soc., and T. R. Jonzs, F.G.S. 
[Continued from vol. v. p.477.] 
32. Orbulites marginalis. Hist. An. s. Vert. ii. p. 196, No. 1. 
“Recent ; European Seas; discovered by M. Sionest on Coral- 
lines, Fucus, &c.” 
_ Under this name Lamarck placed the living European Ordi- 
tolites, which, though smaller than the fossil specimens from 
Grignon (and than the Australian and South Sea individuals), 
doubtless belong to the same species, O. complanata. 
33. Orbulites lenticulata. Hist. An. s. Vert. ii. p. 197, No. 3. 
“Q lentiformis, superne convexa, subtus planiuscula. Habite, 
—-se trouve fossile 4 la Perte du Rhone, prés du Fort de l’Ecluse, 
& huit lieues de Genéve. Elle y forme des masses considérables. 
M. Brard. Mon cabinet.” 
According to Bronn, this fossil was named Madreporites lenti- 
cularis by Blumenbach, 1805, Naturhist. Abbild. Nr. u. Fig. 80. 
It has been recognized by D’Orbigny as a Foraminifer. In his 
‘Cours Elém,’ ii. p. 193, and ‘ Prodrome,’ ii. p. 143, he gives it 
the generic name of Orbitolina, and regards it as “an unsym- 
metrical Orbditolites coated with encrusting cells on one side.” 
This we do not accept as a correct definition of its relationship. 
Our views of the structure and relationship of this form will be 
best understood if we trace it from its simplest variety to its 
highest state of development. It is among both recent and 
fossil specimens, from many parts of the world, that we collect 
our materials for the elucidation of this protean and hitherto 
misunderstood Rhizopod. 
1. Among the abundantly varied Foraminifera from the Ter- 
tiary beds of Grignon we find a very minute, smooth, scale-like 
shell (about =1,, inch in diameter), thin, transparent, and sparsely 
perforate, and consisting of a circular, subconical, tent-like top 
covering one or two relatively large subannular chambers, which 
are not distinctly separate. 
Seen from below, these chambers, occupying the greater part 
of the hollow of the tent or shield, present a convex aspect, with 
a central pit or umbilicus,—the outer and lower, or marginal, 
portion of the shield bearing very slight indications of annular 
septal markings, left probably by the sarcode that occupied the 
concavity. 
Seen from above, or from the side, this little subconical shell 
presents (by transparency) faint appearances of three whorls of 
a spire due to the first and second cells (the latter being some- 
what semilunar) and the outer rudimentary septum. We name 
this variety Orbitolina simplex. 
