90 
AViLLiAMSON on Faujasina. 
tainly crossed the second one (see fig. 3), which is seen at 
along with four others, 5, c, c/, and e, in the order of their suc- 
cessive development. Whilst their inferior portions of the seg- 
ments are nearly on an uniform level, the upper extremites of 
those belonging to successive convolutions become rapidly 
elongated, leaving between them a large, irregular, conical 
space (fig. 5 ^, g\ the inverted apex of which rests upon the 
most central segment (5 ol) and communicates with the inferior 
surface by means of the canals fig. 5 li' . Similar canals are 
also seen at 5 ^, passing upwards into the inter-septal spaces ; 
whilst at 5 i i\ corresponding ones proceed inwards through the 
respective septa of the cells c and d — in the translucent walls 
of the latter of which their direction, and the extent of the 
inter-septal space may be traced. 
I have not in any one instance found these spaces, or their 
divergent canals, communicating with the interiors of the seg- 
ments, though at the first glance many of them appear to do 
so, as is the case with the inner margin of the large segment 
fig. 5 But from the examination of a considerable number 
of sections, I am satisfied that where such an appearance exists, 
it is either the result of an accidental fracture or an optical 
illusion ; and that the only direct communications existing 
between the two parts of the organism, are through the pseu- 
dopodian foramina, many of which open into the tubular por- 
tions of these passages (figs. 3 d and 4y) ; but never, as far as 
I have observed, into the intra-septal spaces. 
But the section now under consideration, in common with 
several of the others just described, presents a new and curious 
feature. The cavities in the translucent calcareous shell are 
thickly lined with a dark olive-brown substance, apparently 
the residuum of the soft animal. This substance not only 
exists in the interior of all the segments, closing up the oral aper- 
tures, as at 5/", but also occupies the intra-septal spaces and 
their respective canals, as well as the irregular cavity in the 
umbilical centre of the shell. If this substance is really the 
desiccated soft animal — and of this we should not have enter- 
tained a doubt, had it existed only in the interior of the seg- 
ments — it is evident that in this species the gelatinous tissue 
has not only filled the true chambers but has also occupied 
the intra-septal canals and passages. The specimen from 
which the section, fig. 4, was prepared, exhibited the same 
appearance, and traces of it occur in all ; hence it appears most 
probable that this brown substance is really the desiccated soft 
animal. If this should prove to be a correct conclusion, it is 
curious that the only medium of communication between the 
soft tissues inhabiting the spiral segments of the shell and those 
