ready means of escape by flight or concealment from their enemies. We learn from Geology that this Order began to exist nearly at the same time with the Order of Saurians, and has continued co-extensively with them through the secondary and tertiary formations, unto the present time: their fossil remains present also the same threefold divisions that exist among modern Testudinata, into groups respectively adapted to live in salt and fresh water, and upon the land.
Animals of this Order have yet been found only in strata more recent than the carboniferous series.[1] The earliest example recorded by Cuvier, (Oss. Foss. Vol. 5, Pt. 2, p. 525,) is that of a very large species of Sea Turtle, the shell of which was eight feet long, occurring in the Muschelkalk at Luneville. Another Marine species has been found at Glaris, in slate referable to the lower cretaceous formation. A third occurs in the upper cretaceous freestone at Maestricht. All these are associated with the remains of other animals that are marine; and though they differ both from living Turtles and from one another, they still exhibit such general accordance in the principles of their construction, with the conditions by which existing Turtles are fitted for their marine abode, that Cuvier was at once enabled to pronounce these fossil species to have been indubitably inhabitants of the sea.[2]
- ↑ The fragment from the Caithness slate, engraved in the Geol. Trans. Lond. V. iii. Pl. 16, Fig. 6, as portions of a trionyx, is pronounced by M. Agassiz to be part of a fish.
- ↑ Plate 25', Fig. 4, represents a Turtle from the slate of Glaris: it is shown to have been marine by the unequal elongation of the toes in the anterior paddle; because, in freshwater Tortoises, all the toes are nearly equal, and of moderate length; and in land Tortoises, they are also nearly equal, and short; but in marine species they are very long, and the central toe of the anterior paddle, is by much the longest of all. The accordance with this latter condition in the specimen before us, is at once apparent; and both in this respect and general structure, it approaches very nearly to living genera. This figure is copied from Vol.
