90 
DISTRIBUTION OF ANIMALS. 
[PART 1. 
The two next orders consist of but a single family each, viz. : 
Order Fam. 
PROBOSCIDEA ... 53. Elephantidae Elephants. 
IIYRACOIDEA ... 54. Hyracidse Rock-rabbits. 
We now come to the llodentia, a very extensive and difficult 
order, in which there is still much difference of opinion as to 
the details of classification, although the main outlines are pretty 
well settled. The foundations of a true classification of this 
order were laid by Mr. G. It. Waterhouse more than thirty years 
ago, and succeeding authors have done little more than follow 
his arrangement with unimportant modifications. Professor 
Lilljeborg, of Upsala, has however made a special study of this 
group of animals, and has given an original and detailed classifi- 
cation of all the genera. (Systematisk Ofvcrsigt af dc Gnagande 
Daggdjuren , Glires. Upsala, 1866.) I follow this arrangement 
with a few slight modifications suggested by other naturalists, 
and which make it better adapted for the purposes of this work. 
Order— RODENTIA. 
Simplicidentati 
Murina 
(Waterhouse) 
Hystricina 
(Waterhouse) 
Duplicidentati j (Waterhouse) 
55. Murida* 
. . . Rats. 
56. Spalacidaj 
. . . Mole-rats. 
57. Dipodidee 
... Jerboas. 
58. Myoxidaa 
... Dormice. 
59. Saceomyidaj ... 
... Pouched Rats. 
GO. Castoridoe 
. . . Beavers. 
61. Sciuridaj 
. . . Squirrels. 
62. Haploodontidoa 
. . . Sewellels. 
63. Chinchillidffi . . . 
. . . Chinchillas. 
64. Octodontidie ... 
. . . Octodons. 
65. Echimykhe 
. . . Spiny Rats. 
G6. Cercolabida? ... 
. . . Tree Porcupines. 
67. Hystricidic 
. . . Porcupines. 
68. Caviidee 
. . . Cavies. 
69. Lagomyidae . . . 
... Pikas. 
70. Leporidte 
. . . Hares. 
The Edentata have been classified by Mr. Turner, in the 
Proceedings of the Zoological Society (1851, p. 205), by Dr. 
Gray in the British Museum Catalogue, and by Professor Cams 
in his Handbuch. The former takes a middle course between 
