564 Classification of Animals. 
late Mr Bennet, who had deeply studied the structure and affinities 
of the marsupial animals ; and we consider the act alone of break- 
ing up an order so artificial, and the arrangements of its contents 
more in accordance with their affinities and general organization, an 
attempt well deserving the thanks of the naturalist. 
The notice of the Cetaceae or aquatic order, as might be expected 
from our comparative ignorance of the habits of the species, and the 
paucity of the types discovered, is very brief, and no attempt is 
made to determine the natural divisions. Its connection with the 
Ferae is supported by the affinity that the Phocidce evidently show 
to the Dugongs or herbivorous whales, which latter animals also 
serve to connect the Cetaceous order with the Ungulata, by means 
of the Hippopotamus ; but no forms have yet been discovered to 
show in what manner its union with the Glires is effected. The 
Ungulata or hoofed order which follows, are known <c by the pecu- 
liar construction of their feet, the extremities of which are entirely 
surrounded or inclosed in a horny covering or sheath, a structure by 
which they are distinguished from all the other land quadrupeds, 
whose toes are merely tipped with claws, or protected outwardly 
by nails. The primary divisions or tribes of this conspicuous group, 
are, according to our author, the Solipedes, of which the horse is 
typical ; the JRuminanles, distinguished by their cloven hoofs and 
horns ; these two represent the typical and subtypical divisions. The 
aberrant are the Anoplotheres, so named in reference to their fossil 
type, supposed to be now represented by the tapirs, pigs, &c. The 
Pachydermes, containing the largest existing land animals, as the 
elephant, rhinoceros, &c. and the Edentates, forming the most 
aberrant division of the order, this group, he remarks, forms a soli- 
tary exception to all the preceding, in having distinct toes, and 
very large nails ; but those nails are unlike those of all other qua- 
drupeds, and M. Cuvier well observes, " that they approach more 
or less to the nature of hoofs." The circular series of these divisions 
he endeavours to trace in the following manner : The Solipedes 
pass into the Ruminants by the camel ; the tapirs, which show an 
intermediate form between the ruminants and the armadilloes, 
connect the Anopletheres with the Edentates ; the Sloths, which 
belong to the latter, lead directly to the fossil genus Megatherium, 
in the circle of the Pachydermes, and the return to the Solipedes is 
supposed to be effected by means of the hippopotamus ; though we 
confess the affinity seems distant, and that some intermediate forms 
are wanting to bring these divisions into juxtaposition. After a 
