There is less to be said about the animals found fossil in the coal than about the plants. And for this reason, that the vegetables formed the coal; the shells and crustaceous creatures, and fish, and reptiles, were but visitors: or if they lived upon the spot, bore no larger proportion to the stately jungle that sheltered them, than the denizens of our own forests now-a-days do to the trees and undergrowth which give them food and habitation.

Still, animals are far from rare; and the common ones are chiefly bivalve shells and worms. The truly land animals are but few. A rare insect or two has been found in our own country. Dr. Mantell discovered the wing of a fly not unlike the dragon-fly, and supposed to belong to the American genus Corydalis. This insect is figured in Sir R. I. Murchison's Siluria, and is now in the British Museum. And one or two beetles, or rather what have been supposed to be beetles, have been found in Coalbrooke Dale. Cockroaches and crickets have left their wings in tolerable plenty in the coal-shales of Saxony. No doubt they were welcome there amid the coal-solitudes, and put a little life into them. They are far from welcome now. I recommend all who may live in the neighbourhood of the coals to give a little time to hunting for the relics of these old insects, &c.

But there are other causes that have tended to modify animals; stich as habit, use or disuse of any particular organ, food, climate, &c., and these together with the fact that a variation which appears in the parent, at any period of its existence, tends to re-appear in the offspring at the same period, will enable us to account for the metamorphoses of insects, the differences of colour in the young and the adult, the horus of sheep and cattle, &c. If to these we add that of “sexual selection,” we can see why sexes differ in organs and properties. In fact most of the facts in natural history can be explained by this theory; but there are a few which at present cannot, such as the colours of certain larvæ, which are asexual. Even these may perhaps be the effects of the mysterious and unknown laws of correlation of growth and sympathy between different parts.

We must remember that the theory of natural selection is subordinate to, and totally distinct from, that of the transmutation of species; and that if the former should be found wanting it would not effect the latter in the least degree.

The third great argument urged against the theory of transmutation of species is the geological one; and may be divided into two heads.

In addition to the Brachiopoda noticed in this paper, I am possessed of various minute specimens, which differ from any described species. Some of these may be the young of Brachiopoda that occur in the beds in which they are found; but until their passages into adult shells can be satisfactorily recognized, it will be undesirable to figure or describe them. Three examples of well marked and persistent forms are provisionally named and given below.

Spirifera minima. Moore. Pl. ii., figs. 19, 20.

Shell microscopic, often one sided or unsymmetrical, slightly rugose; valves moderately convex; deltidium triangular; area broad and flattened; hinge-line broad; front of shell rounded, In some specimens the shell presents a uniformly flattened surface, whilst in the majority the outer surface of the smaller valve possesses mesial folds, and in the larger valve a central sinus.

Obs.—This shell is not uncommon in the Inferior Oolite of Dundry. Although no internal characters have yet been noticed, there seems little doubt the shell must be referred to the genus Spirifera. It is perfectly distinct from a little shell found with it, described by me in the Somersetshire Proceedings for 1854. We have thus evidence of the presence of two species of this genus in oolitic strata, although in both instances they have become very degenerate in size. No larger specimens of the genus have yet been found in the same beds to which these diminutive shells can be referred.

Terebratula (?) minuta. Moore. Pl. ii., figs. 21, 22.