If, during the Coal-period, the vegetable kingdom had reached its maximum, the animal kingdom, on the contrary, was poorly represented. Some remains have been found, both in America and Germany, consisting of portions of the skeleton and the impressions of the footsteps of a Reptile, which has received the name of Archegosaurus. In Fig. 68 is represented the head and neck of _Archegosaurus minor_, found in 1847 in the coal-basin of Saarbruck between Strasbourg and Trèves. Among the animals of this period we find a few Fishes, analogous to those of the Devonian formation. These are the _Holoptychius_ and _Megalichthys_, having jaw-bones armed with enormous teeth. Scales of _Pygopterus_ have been found in the Northumberland Coal-shale at Newsham Colliery, and also in the Staffordshire Coal-shale. Some winged insects would probably join this slender group of living beings. It may then be said with truth that the immense forests and marshy plains, crowded with trees, shrubs, and herbaceous plants, which formed on the innumerable isles of the period a thick and tufted sward, were almost destitute of animals. [Illustration: XI.--Ideal view of a marshy forest of the Coal Period.] [Illustration: Fig. 65.--Sigillaria reniformis.] [Illustration: Fig. 66.--Asterophyllites foliosa.] On the opposite page (PL. XI.) M. Riou has attempted, under the directions of M. Deslongchamps, to reproduce the aspect of Nature during the period. A marsh and forest of the Coal-period are here represented, with a short and thick vegetation, a sort of grass composed of herbaceous Fern and mare’s-tail. Several trees of forest-height raise their heads above this lacustrine vegetation. On the left are seen the naked trunk of a _Lepidodendron_ and a _Sigillaria_, an arborescent Fern rising between the two trunks. At the foot of these great trees an herbaceous Fern and a _Stigmaria_ appear, whose long ramification of roots, provided with reproductive spores, extend to the water. On the right is the naked trunk of another _Sigillaria_, a tree whose foliage is altogether unknown, a _Sphenophyllum_, and a _Conifer_. It is difficult to describe with precision the species of this last family, the impressions of which are, nevertheless, very abundant in the Coal-measures. [Illustration: Fig. 67.--Annularia orifolia.] [Illustration: Fig. 68.--Head and neck of Archegosaurus minor.] In front of this group we see two trunks broken and overthrown. These are a _Lepidodendron_ and _Sigillaria_, mingling with a heap of vegetable débris in course of decomposition, from which a rich humus will be formed, upon which new generations of plants will soon develop themselves. Some herbaceous Ferns and buds of _Calamites_ rise out of the waters of the marsh.