232 
DR. carpenter’s RESEARCHES ON THE FORAMINIFERA. 
which extend from the annular passages of each zone to the cells of the next, 
and, in the outermost zone, to the pores d, d ; — another portion as displayed 
by a vertical section e, e, in a radial direction, which lays open the colum- 
nar cells, but passes through the intercellular partitions, in alternate zones; 
— and another portion ff, as displayed by a fracture in the course of one of 
the zones, laying open the entrances to the cells from its inner or central 
side. 
Figs. 2, 3. Two large recent disks from the Feejee islands, plicated towards the mar- 
gin, but one much more so than the other, and with a projection of the 
upper and lower edges, so as to leave a deep marginal furrow : — enlarged 
2 diam. 
Figs. 4, 5. Vertical sections of two disks, drawn under the same magnifying power, 
showing the marked difference in the size and proportions of their parts. 
In each disk we see the central cell, with the circumambient cell laid open 
on either side of it ; and the cells of successive zones, with their commu- 
nications : — 30 diam. 
Fig. 6. Ideal Representation of a Disk of the Complex Type ; the details of the 
different parts made-up from actual specimens ; — a, central cell ; h, circum- 
ambient cell ; c, c, concentric zones of oblong superficial cells, some of 
them laid open ; d, d, marginal pores, forming several rows ; d", d'", cor- 
responding pores of inner zones, once marginal, but now connecting them 
with surrounding zones; e, e, vertical section in a radial direction, show- 
ing the zones nearest the centre to be made up of simple columnar cells, 
but those of the remainder of the disk to be composed of two superficial 
layers and of an intermediate stratum ; f,f, floors of the superficial cells, 
with an aperture at each end of every one ; g, g, annular canals, running 
beneath these floors, with the large apertures leading to the columnar cells 
of the intermediate stratum ; g', the same canals near the other surface of 
the disk ; g", the same canals laid open through the plane at which they 
give off the two passages into the superficial cells ; g’", the same canals, as 
cut transversely by a vertical section ; h, passage of the horizontal section 
through the intermediate stratum, showing the summits of its columnar 
cells about to enter the annular canals ; i, i, i, and k, k, k, passage of the 
horizontal section through two different planes of the intermediate stra- 
tum, showing the connexion between the columnar cells of successive zones, 
by oblique passages running in different directions ; I, portion immediately 
surrounding the nucleus, formed upon the simple type, as in fig. 1. 
Fig. 7- Vertical section, taken in a radial direction, of a recent disk incompletely 
developed on the complex type ; showing at a, a single chamber of the cavity 
of the nucleus, the section having traversed the circumambient cell; from 
a to h, including twenty-three zones, the disk developed upon the simple 
