159 
Plate X. Fig. 28. It is rather rough and scabrous ; partly from the 
removal of some small portions of its surface, and partly from the adhe- 
rence of some of its calcareous matrix. On being viewed with a lens, 
it presents the appearance Plate X. Fig. 30. The tubes are seen to be 
distinct ; and, where the outer surface has been removed, the conca- 
merations are perceived, resulting from the interposition of very nu- 
merous and minute septa, transversely disposed. These tubes narrow 
as they approach to their terminations, and as may be seen in Fig. 29, 
which represents one of the ends of the fossil magnified, the end of 
each tube overlaps that of the preceding. That this is the case, and that 
these tubes are placed perpendicularly round the centre, is evident, 
from the appearance of the longitudinal section, Fig. 31, in which 
a section is seen of the central and surrounding tubes, divided into 
compartments by their small and numerous septa. 
From this examination it appears, that round the small first-formed 
tube, or chamber, successive increasing columnar tubes were disposed 
folding over each other at their ends. Whether these several tubes 
were, as it is most probable, internally connected with each other, or 
not, or whether the chambers communicated, or not, with each other, 
by a siphuncle ; are questions, which must remain to be answered by 
the examination of some more illustrative specimen. Like some of the 
nummulites, this body, when polished, has more the appearance of 
bone than of shell. From this circumstance, as well as from the 
number and appearance of its septa, I am disposed to consider this 
body as approximating nearer to the nummulite than to any other fossil. 
LXXXIY. Discorbis. A spiral discoidal univalve ; the turns all 
contiguous, uncovered, and perceptible. The septa transverse, whole, 
and frequent. 
Lamarck, who has seen these shells only fossil, supposes them to be 
known only in that state, and wishes that circumstance to be pointed 
out by the termination of the name of the genus, Discorbites. It is said 
