. Natural history. Zoology. FUj. S,—Matamata (Chelys fimhriata). genera, namely Uydrnspis, lihinemys, and Phdemys, have the neck propor- tionately shorter. Three generic types of the family are met with in Australia and Papua, one of which (Oltdodiiia) has the neck very long, while in the other two {Elseiia and Mmyduni) it is relatively shorter. The largest member of the whole sub-order is the great fresh-water tortoise of the Amazons (Podocnemis expansa), whose shell often measures two-and-a- half feet in length. Together with its allies, this species belongs to the second family of the sub-o
. Natural history. Zoology. FUj. S,—Matamata (Chelys fimhriata). genera, namely Uydrnspis, lihinemys, and Phdemys, have the neck propor- tionately shorter. Three generic types of the family are met with in Australia and Papua, one of which (Oltdodiiia) has the neck very long, while in the other two {Elseiia and Mmyduni) it is relatively shorter. The largest member of the whole sub-order is the great fresh-water tortoise of the Amazons (Podocnemis expansa), whose shell often measures two-and-a- half feet in length. Together with its allies, this species belongs to the second family of the sub-order, characterised Family by the presence of a pair of mesoplastrals between the liyo- Pdomedusidce. and hypoplastral bones, the total number of elements in the lower shell thus being brought up to eleven. The neck can be fully with- drawn into the shell, and the skull has a lateral bony arch. The genus Podocnemis affords a remarkable example of discontinuous geographical dis- tribution, six of the species being inhabitants of South America, whereas the seventh is found in the distant island of Madagascar. In this genus the hinder part of the skull is completely roofed over by bone ; but this is not the case in the other two genera of the family. Of these, Pdo- medusa, which has only a single species, both Madagas- car and Africa, resembles Podo- cni' in that the two mesoidas- tral bones only show themselves on tlie sides of the lower sliell, and are thus widely separate in the middle line. On the other hand, in Stciiiothcer'is the same two bones are as fully developed as the other elements of the plastron, in the median line of which they come into contact with oneanother. The whole of the species of this genus are Afiican, but one ex- tends its range into Fig. 9.—Amazonian Fresh-Water Tortoise (Podocnemis expansa). The great Amazonian species of Podocnemis is of considerable value to the natives of some parts of tropical America, on account
Size: 1811px × 1379px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorly, bookcentury1800, bookdecade1890, booksubjectzoology
