Dr. W. B. Carpenter on the Foraminifera. 209 
has been surrounded by another, this radiating canal-system of the 
inner whorl does not usually continue itself directly into that of the 
outer (though such a continuation is not unfrequently seen), but 
the diverging canals for the most part terminate in the stolons of 
communication between the segments of sarcode that occupy the 
chambers of the outer whorl. 
The evidence afforded by the distribution of the canal-system in 
Polystomelila is decidedly confirmatory of the view expressed by the 
author on a former occasion, that this peculiar set of inosculating 
5 passages is related to the formation and nutrition of those solid 
calcareous layers which strengthen and connect the proper walls of 
the chambers, and to which he has given the designation of the 
“intermediate skeleton.” 
This view derives strong confirmation from the still more extensive 
distribution and greater importance of the canal-system of Calcarina, 
a genus of which Mr. Cuming’s Philippine collection affords a most 
remarkable series of illustrations. This type may be considered as 
closely allied to Polystomella in the disposition and mode of com- 
munication of its chambers, save that the spire is generally more or 
less inequilateral. Its ‘intermediate skeleton’’ is, however, much 
more developed ; and it extends itself into a variable number of pro- 
longations, sometimes simply club-shaped, sometimes more or less 
ramifying, which radiate in different directions from the central body, 
giving it somewhat the appearance of a spur-rowel, whence its 
generic designation. (An approach to this configuration is occasion- 
ally presented by the common Polystomella crispa, as also by 
some other species of Polystomella.) Now the independence of the 
intermediate skeleton and of the spiral system of chambers is curi- 
ously shown by the disproportionate development which they respect- 
ively exhibit the one to the other, and by their occasional complete 
disconnexion,—the spire altogether departing from its usual course, 
and (as it were) running wild, whilst the intermediate skeleton 
with its prolongations still presents its ordinary configuration. ‘The 
nutrition of the intermediate skeleton seems to be provided for by a 
system of large canals, freely inosculating with each other, which 
originate on the sides of the chambers, and are continued through 
$ the whole thickness of the intermediate skeleton, some of them pass- 
: ing directly to its nearest surface, whilst others are continued to the 
terminations of its radiating prolongations. 
It is nota little remarkable that a Foraminiferous organism should 
present itself so extremely resembling the preceding as to be easily 
mistaken for it, and yet essentially differing from it in its plan of 
structure. This is the case with a type of which some remarkable 
Specimens occur in Mr. Cuming’s collection, and of which some 
smaller examples have been kindly put into the author’s hands by 
Dr. J. E. Gray. As it seems to be identical with the body described 
by Montfort under the designation Tinoporus baculatus, it may be 
right to retain that name, although it had been abandoned under 
the impression that it was a mere synonym of Calcarina. The 
structure of this body will be better understood after the description 
