588 
DE. CAEPENTEE’S EESEAECHES OX THE EOEA^UXETEEA. 
and showing at «, «, «, the csecal diverticula for the retral processes, and at 
the meridional canals transversely divided. Magnified 60 diameters. 
Fig. 11. Portion of a section of Polystomella ci'oMculata taken in the same dkection as 
that represented in fig. 2, and showing the origin of the canals which pass 
vertically through the solid umbilical nucleus, and whose external orifices are 
seen at <?, from the successive turns 5, 5, h of the spiral canal, which are seen 
transversely divided at a. Magnified 80 diameters. 
Fig. 12. Portion of a section which has passed close to the lateral surface of one of 
the outer whorls, in such a manner as to show a portion of its spiral canal, 
with four of the meridional canals passing do'VMi the intraseptal spaces, and 
giving otf successive pairs of diverging branches; between the septa from 
which they proceed is seen the finely-tubular substance foiming the proper- 
wall of the chambers. Magnified 80 diameters. 
Fig. 13. Portion of a section passing through the median plane of the outer whorl, 
showing some minute shells of the foraminiferous tj'pe in the ca-^ity of thi-ee 
of the chambers. Magnified 100 diameters. 
PLATE XVIII. 
The figures in this Plate refer to Polystomella craticulata, and to Tinojyorus haculatus. 
Fig. 1. Ideal representation of a specimen oi Polystomella craticulata, laid open to show 
its internal structure : a, a\ chambers of three whorls which are laid open 
by the plane of section ; b, h\ P, septa of four whorls altei-nating with the 
preceding, which are traversed by the plane of section ; c, c', c", septal aper- 
tures ; dd', ddJ, dd', meridional canals ; e, e, e, and d, e', e', orifices of the suc- 
cessive turns of the two spiral canals (of which the upper one is displayed by 
the supposed removal of the umbilical nucleus) transversely dhided ; f\f, con- 
verging canals, passing inwards from the meridional canals ; gg', gg', gg', surface 
of the last-formed portions of the spiral lamina, showing a row of fiu'rows 
passing across between the septal bands, into which the diverging canals open 
in immediate contiguity to the septal bands; hh', Jih', older portion of the 
spiral lamina, showing the replacement of each series of furrows by two rows 
of punctations ; ii', ii', surface of the interior whorl, showing the obliteration 
of the septal bands and the rows of dimpled depressions into which the 
diverging canals open. 
Figs. 2, 3, 4, 5. External aspect of specimens of Tinojgorus baculatus from Borneo and 
Australia, showing the ii-regularity of their radiating prolongations. Mag- 
nified 20 diameters. 
Fig. 6. A specimen of the same more enlarged, showing the areolated character of the 
surface of the disk, with elevated tubercles disposed between the areokn, and 
