98 



CLASS KEPT ILIA. 



ORDER CHELONIA 



CLASS III. K E P T I L I A. 



Reptiles are cold-blooded Animals. Their heart is so constructed, that at each contraction only a small portion of the blood is sent into 

 the lungs, while the greater quantity passes into the general circulation, without having been subjected to the process of respira- 

 tion in those organs : hence they are destitute of the vivacity and muscular energy of warm-blooded Animals, whether Mammalia 

 or Aves. Their movements are slow, and their habits sluggish : their digestion is destitute of vigour, and their sensations are 

 obtuse. Throughout the winter, in cold and temperate latitudes, they remain in a state of torpidity. They are either covered 

 with scales, or only with a naked skin : they can remain a long time submerged, owing to the smalhiess of their pulmonary vessels ; 

 and they are more varied in their form, gait, and characters, than the preceding Classes. The females have a double ovary, and 

 two oviducts : they never incubate their eggs. 



ORDER I. CHELONIA. TURTLES. 



THE Turtles are better known by the appellation of Tortoises. They are 

 enveloped in two bony bucklers, the upper one being called the carapace 

 or shield, and the under one the plastron or breast-plate. They have a 

 heart with two auricles, and a ventricle with two chambers, communicating 

 with one another. 



ILLUSTRATIVE EXAMPLES. 



PUITE 1. 

 Species. 



Genera. 



Testudo - - - 



Kinys ... 



Sternothcerus - 



Chelonia - - 



Chelys - - - 



Trionyx - - - 



Grseca - - - 



Scripta - - - 



Trifasciatus - 



Virgata - - 



Matamata - - 



Nilotica - - 



Common Name. 



Common Tortoise. 



Written Fresh-water Tortoise. 



Three-striped Box Tortoise. 



Striped Turtle. 



Matamata. 



Nilotic Trionyx or Soft Tortoise. 



CHARACTERS OF THE GENERA. 



1. TESTUDO (Lat. testa, a shell). Back-plate and breast-plate firmly 

 united, the former arched, the latter nearly flat ; dorsal plates thirteen, 

 pectoral twelve ; head and legs retractile within the back-plate ; head deep, 

 obtuse ; jaws horny, serrated ; legs club-like ; toes immoveable, enveloped 

 in a common skin, five in front and four behind, their nails large, conical, 

 blunt, and attached around the front of the extremity of each foot. 



2. EMYS. Breast-plate consisting of two equal-sized pieces moving on 

 each other, or of two unequal-sized pieces, of which the anterior only is 

 moveable, or of three pieces, of which the anterior and posterior move upon 

 the fixed middle piece ; beak homy ; scales of the disc thirteen ; toes 

 distinct, slightly webbed, and furnished with long, sharp claws. 



3. STERNOTH<ERTJS. Characters as above ; that part only of the breast- 

 plate being moveable, which is anterior to its bony junction with the back- 

 plate. 



4. CHELONIA. Bony covering too small to receive the head and feet ; 

 feet long, especially the fore feet ; toes united by a membrane. The several 

 pieces of the Plastron not well denticulated, the intervals of which are filled 

 with cartilage. 



5. CHELYS. Envelope small; head and feet large; elongated nose; 

 mouth widely cleft. 



6. TRIONYX. Back and breast-plate not completely sustained by bone, 

 but covered with a soft skin ; lips fleshy ; muzzle elongated and trumpet- 

 shaped; neck long and completely retractile; tail short, and the vent 

 opening at its extremity; feet not lengthy but webbed, each furnished 

 with three clawed toes. 



CHELONIA. DESCRIPTION OF THE SPECIES. 



TESTUDO Land Tortoise. These animals are found in almost all parts 

 of the world except Australia, living in dry districts, and during winter 

 bury themselves deep in the earth. On account of the shortness of their 

 legs they move slowly and awkwardly. They feed on vegetables and fruit, 

 and lay but few eggs, which, however, have hard, unyielding, calcareous 

 shells, and are deposited in holes in the ground. 



Tortoise : under surface. 



The largest of the species is the 

 Tortoise (T. Indica), its back-plate mea- 

 suring from three feet to four feet five 

 inches; and the smallest and most elegant 

 of the family is the Geometric Tortoise, 

 which is generally about five and a half 

 inches in length, four in width, and three 

 and a half in height. The sizes of the 

 other species range between these. 



The illustrated specimen, the Common Tortoise (T. Graeca), is from ten 

 to twelve inches in length, and lives in the woods or on elevated soils, is 

 very fond of warmth and sunshine, and feeds both on the roots of herbs, 

 fruits, insects, and worms, and also on snails, the shell of which it easily 

 breaks with its strong jaws. It is often kept in gardens, as it does no 

 mischief, but destroys noxious insects. In October, they bury themselves 

 as deep as two feet under ground, become torpid, and do not appear 

 again till April. They are long-lived. This species inhabits the islands 

 and the countries bordering on the Mediterranean, and it is the most common 

 in Europe. Their eggs are eaten as food, and the young ones also by the 

 Greeks, who consider them as much lenten fare as fish. It is this species 

 which was placed by the Grecian sculptor Phidias at the feet of his Venus, 

 as an emblem of gentleness. 



EMYS Marsh Tortoise. A most extensive family, numbering seventy- 

 four species, according to M. Bibron. Their general characteristics are 

 those of the genus Testudo ; their shell is, however, flatter, their toes are 

 more widely separated, and they are webbed, and armed with long sharp 

 nails. They tenant swamps, lakes, ponds, and small rivers, and owing to 

 the structure of their feet, they swim with considerable facility. They are 

 also active on land, but they do not venture far from the water. They 

 are carnivorous, preying on insects, frogs, newts, and even fishes. Some 

 of the species (e. g., the Alligator Tortoise) are large and ferocious, and 

 dangerous even to man. 



STERNOTHffiRUS. The illustrated species, the Three-striped Tortoise, 

 (Terrapene Trifasciatus) has a long, narrow head, somewhat depressed, 

 with a lengthy beak ; from each nostril passes across the orbit to the back 

 of the head, where they join, a deep brown band; neck long, ashy above 

 and yellow beneath ; dorsal plate oval, broader behind, its margin slightly 

 indented, and the dorsal ridge carinated ; its horny plates very thin, slightly 

 wrinkled, and striated on their edge; marginal plates twenty-five; hind 

 part of the breast-plate notched, and so close to the back-plate as to render 

 the posterior aperture for the thighs very narrow ; tail long and slender ; 

 general colour of the back-plate light dull yellow, intermixed with ml and 

 black markings; breast-plate black, with a light edge and o nin . Tinw- 

 are three other species. 



CHELONIA. The species are the KdiUe, or Green Turtle (T. Midas ) ; the 

 Imbricated Turtle, and the Hawk-billed Turtle (T. Caretta) ; also C. Mani- 

 losa and C. Lachrymata, nearly connected with the Edible Turtle, and the C. 

 Radiata and C. Virgata (Plate 1), closely allied to the Imbricated species. 



The Striped Turtle (C. Virgata) has raised scales, with pointed lateral 

 angles, and radiating black lin 



