72 
TORTOISES AND TURTLES. 
Thick-Necked Nearly allied to the preceding is the thick-necked terrapin 
Terrapin. (Bellia crassicollis), from Tenasserim, Siam, the Malay Peninsula, and 
Sumatra, which, with a second species from Borneo, constitutes a genus dis¬ 
tinguished by the greater development of the bony buttresses connecting the upper 
with the lower shell, and by the hinder part of the head being covered with small 
horny shields. The feet are fully webbed, and the anterior vertebral shields of the 
carapace are more or less distinctly balloon-shaped. The typical species measures 
rather more than 6J inches in length; and is of a general dark brown or black 
colour, usually with some yellow markings on the plastron, and some large spots 
of the same colour on the head. Several representatives of this genus are met 
with in a fossil state in the Pliocene deposits of North-Western India. 
Hamilton’s The handsomely coloured Hamilton’s terrapin (Damonia hamil- 
Terrapin. toni), from India, conspicuous for its black and yellow, highly 
vaulted, and three-keeled carapace, is the best known representative of a third 
genus, distinguished from the foregoing by the 
hinder aperture of the nostrils opening behind 
the line of the eyes, and the great breadth of 
the palate. Like the two preceding genera, the 
entoplastral bone of the plastron is traversed by 
the groove formed by the union between the 
humeral and the pectoral shields ; and the hinder 
part of the head is covered with small shields. 
Hamilton’s terrapin has the elevated carapace 
marked with three interrupted longitudinal keels, 
or rows of nodose prominences; the colour of the 
shell being dark brown or blackish, upon which 
are spots and streaks of yellow, and the soft parts 
having likewise a similar coloration. While in 
young individuals the hinder border of the 
carapace is strongly serrated, in the adult it 
becomes nearly smooth. This species attains a 
length of nearly 9 inches at the present day, but 
fossil examples found in the Pliocene rocks of Northern India were still larger. 
These fossil specimens lived with numbers of mammals belonging entirely to 
extinct species. There are four other species of the genus, ranging over Malayana, 
Southern China, and Japan. 
Salt-Water The last representative of the group with a smooth palate and 
Terrapin. carnivorous habits is the North American genus Malacoclemmys, 
distinguished from the last by the head being covered with continuous skin, and 
by the groove formed on the plastron by the junction between the humeral and 
pectoral shields being situated in advance of the entoplastral bone. While tw r o of 
the species inhabit the valley of the Mississippi, the salt-water terrapin (M. 
terracin') is a frequenter of the salt-marshes of the Atlantic Coast. The latter 
has an oval and much depressed carapace, which attains a length of nearly 7 
inches, and is characterised by the great width of the first and second vertebral 
shields; its general colour being either olive, with black concentric lines, or 
UPPER SURFACE OF CARAPACE OF 
Hamilton’s terrapin. 
