INHABITING MULTILOCULAR SHELLS. 463 
ver attains the size of an ordinary pin’s head, still, by its indefinite 
multiplication, forms a considerable portion of the mass of the exten- 
sive tertiary formations in the neighbourhood of Paris. Nor is 
this almost incredible abundance of exceedingly small organised bo- 
dies at all so rare as might be expected ; and there is good reason 
to believe that, as science advances, and accurate observation is di- 
rected to the various calcareous sands which are so often met with 
in the older formations, we shall find more and more reason to won- 
der at the profusion of nature at all periods, in giving life to nume- 
rous minute species of animals, whose real importance in the great 
general system is a matter yet to be clearly explained. 
This genus—the “ Miliola” of Férussac, so called from a fancied 
resemblance to millet-seed—embraces the six genera which compose 
D’Orbigny’s fourth group, and, as we have just mentioned, is ex- 
tremely abundant among the fossils of the Paris Basin. In it the 
chambers are clustered in various modes upon a common axis, each 
chamber being of the whole length of the shell, which is thus gra- 
dually enlarged, very much as we may conceive the successive coats 
of a bulb, such as the onion, to increase the whole in length as well as 
thickness ; only it must be remembered that the size of the last cham- 
ber is not quite sufficient to surround the former ones, and the result 
in this, as in most of the Foraminifera, is an odd anomalus appear- 
ance, very difficult to describe, and which can only be understood by 
studying the models of the principle microscopic genera, invented by 
M. D’Orbigny. As many as forty-one species of this interesting 
group are found fossil, more than half of them in the neighbour- 
hood of Paris. The whole number of species known, including the 
recent ones, amount to about a hundred. 
The fifth and last of the great sub-division of the Foraminifera, 
according to M. D’Orbigny’s classification, is marked by the separa- 
tion of the chambers into numerous cavities, by partitions or small 
tubes. There are five genera and but nineteen species referred to 
this group: nine of the species occur fossil, but no very particular 
interest attaches to any of them, although one genus, the—“ Fabu- 
laria”—possesses a very remarkable structure, the chambers being 
divided into a great number of tubes, and having many apertures 
placed alternately at either extremity, 
Such is a faint sketch of a branch of natural history, perhaps the 
most curious, as it is undoubtedly the most obscure and difficult, of 
any that has hitherto attracted the attention of scientific men. Our 
outline is, as might have been anticipated, crude, dry, and incom- 
plete: it is, for the most part, a mere statement of names and num- 
