a new Genus of Foraminifera. — 341 
that this is the usual order of growth; and as, in the only two 
instances I have seen of segments having the central pillar in- 
complete, the portion formed was attached to the inner surface 
of the apex of the enveloping chamber, I am disposed to think 
that, as a rule, this portion of the shell is built up on an ento- 
solenian plan. It occasionally happens (as in fig. 5) that, on 
breaking a shell, the central column remains attached to the 
inner chamber, leaving the outer one at its point of union ; but 
this is quite an exceptional case; for in a very large majority 
of instances the fracture takes place at the opposite extremity. 
On the other hand, the tendency to entosolenian growth. is 
evinced strikingly in the somewhat anomalous condition of the 
first and second chambers of a large specimen shown in fig. 11, 
in which the primordial chamber, containing nothing requiring 
support, has a rudimentary tongue-like extension of  shell- 
substance from the interior apex. It may be noted, also, that 
Signor Seguenza figures one of his varieties without any ex- 
ternal tube. I suspect, therefore, that, having found in one or 
two instances an ectosolenic tube arising from the breaking- 
away of an enveloping chamber, the conclusion has been drawn 
without further investigation that specimens not presentin 
this outgrowth were imperfect. I speak with considerable 
reservation, as none of the specimens which have fallen into 
my hands had an ectosolenian neck, or indeed any evidence 
that such had ever existed. 
But, recognizing the fact that the central column is not the 
counterpart of the produced septat-orifice seen in many Nodo- 
sarine, in other words, that it is not a stoloniferous tube, we 
have still to find how communication between the chambers is 
kept up—a matter of greater difficulty than at first sight ap- 
pears, on account of the extreme brittleness and delicate tex- 
ture of the shell. The condition shown in fig. 11, being in 
other ae monstrous, is of little value as an indication that 
the septal orifice may occur at the summit of the central co- 
tumn ; nor is it needful to dwell upon it, inasmuch as I have 
never seen another example with similar characters. The 
usual form of the aperture is that of a curved slit, either entire or 
bridged over here and there, situate at a little distance from the 
riphery of the column, and to some extent concentric with it. 
he only two perfect specimens which I have left are almost 
exactly alike in the aspect of the exterior aperture ; and fig. 8, 
drawn from one of them, would answer equally well for either. 
The projecting tongue of shell-substance in the centre is some- 
what raised, and has a valve-like appearance on being viewed 
more laterally. In figures 9 & 10 the septal orifices of cnner 
chambers are shown, one of them with, the other without, the 
