Читать книгу Natural History: Reptiles - Philip Henry Gosse - Страница 11

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The species belonging to this genus, which includes the majority of those known, are distinguished by the following characters. The carapace is surrounded by a cartilaginous circumference, very wide, floating behind, and deprived of bone externally. The hinder part of the plastron is too narrow to hide the posterior limbs completely, when the animal draws them up under the carapace.

The common Soft Tortoise of North America ​(Trionyx spiniferus, Lesueur) inhabits the great lakes, and many of the rivers of that continent. It is a ferocious tyrant of the waters, devouring ducks and other fowl, the young of alligators, and fishes, with great voracity. It attains a large size.

SOFT TORTOISE.

Pennant mentions some which weighed seventy pounds; one which he kept for three months weighed twenty pounds, and the buckler or carapace of this specimen was twenty inches in length, while the neck and head measured thirteen inches and a half more. The upper parts vary in tint, being brown or grey of various shades, irregularly marbled, and frequently studded with dots: the under surface is whitish, or of the same tint as the human nails.

Towards the end of April or May, according to M. Lesueur, the females of this species crawl out of the rivers, for the purpose of seeking out places suitable for the deposition of their eggs. Sandy spots exposed to the sun are chosen, and ​to obtain these they will often scale a steep bank that is ten or fifteen feet above the water's edge. The eggs are deposited in hollows, to the number of fifty or sixty, the old Tortoises laying more than young ones. They are spherical in form; the shell is calcareous but in a slight degree, and is therefore more fragile than that of the eggs of the Emydes that inhabit the same waters. M. Lesueur counted in the ovary of a female twenty ready for laying, and an immense number of others, varying in their dimensions, from the size of a pin's head to the full volume attained when they become covered with the calcareous shell. They are caught by persons who angle for them with a hook and line, baited with a small fish; when drawn on shore they are dangerous, darting the head to the right and left with incredible velocity; they often inflict severe bites on their captors, so that the prudent chop off their heads as soon as they draw them out of the water; the flesh is very delicate in flavour.

It is believed that the Soft Tortoises pair, and that the male remains constantly attached to the same female, two individuals of different sexes being commonly seen together in any given locality.