EXPLANATION OF THE PLATES. 
593 
PLATE XXII. 
All the figures in this Plate refer to Carpenteria. 
Fig. 1. Portion of a group of Car^enterioe growing upon the surface of Porites (coral) ; 
a part of the external wall of the uppermost specimen having been thinned- 
away by acid, so as to show the areolation of its inner surface. Magnified 
5 diameters. 
Figs. 2, 3, 4. Interior of the first-formed chambers of three specimens, showing their 
Globigerine characters and arrangement; at a, a, are shown the remains of 
the yellowish-brown spongeous substance by Avhich those chambers were occu- 
pied. Magnified 50 diameters. 
Fig. 5. Isolated specimen of Caf'pentena on the shell of Pecten^ in which the chambers 
of the last whorl diverge so widely at the base of the cone, as to be in great 
degree separated from each other. Magnified 5 diameters. 
Fig. 6. Portion of the external wall, showing the areolated aspect it derives from the 
gentle convexities into wLich it rises between the reticulations that project 
on its internal surface ; at a is shown the natural external surface on which 
the foramina are regularly disposed ; at h that surface has been removed by 
grinding, so as to bring into view the inner layer of the wall, on which the 
foramina are seen to be deficient along the projecting ribs, but to be more 
closely set together in the portions surrounded by these (see fig. 15). Mag- 
nified 30 diameters. 
Fig. 7. Section of a very flat specimen, parallel to the base of its cone, but not far from 
its apex ; showing at a the vertical funnel transversely divided, at h its com- 
munication with the last chamber, at c its communication with the penulti- 
mate chamber, at d, d\ and three of the complete septa dividing the prin- 
cipal chambers, and at g and y' portions of the canal-system. In some of the 
chambers are seen spicules resembling those of Sponges. Magnified 20 dia- 
meters. 
Fig. 8. Portion of a specimen partially laid open by grinding away the apical portion 
of the cone : a, h, c, d, as in the last figure ; e, e\ secondary septa partially 
dividing the principal chambers, but not extending to their central portion ; 
incomplete septa projecting inwards from the external wall, but not 
crossing the cavity of the chamber to reach the opposite wall. Magnified 20 
diameters. 
Fig. 9. Portion of the upper part of the specimen represented at the top of fig. 1, much 
more enlarged, showing the reticulated arrangement of those incomplete 
septa ; the spaces included in the reticulations are in some instances covered- 
in by a thin layer of the shelly wall which has not been removed ; but in 
most other cases this wall has been eaten away by the acid in the central 
MDCCCLX. 4 I 
