136 PROCEEDINGS OF THE GEOLOGICAL SociETY. [fNov. 3, 
399, touch by the genus Camelus the genus Equus in the contiguous 
circle of Pachydermata. 
In the ‘ Synopsis of the Mammalia in the British Museum,’ 8vo, 
1843, in which Mr. Gray states that “the system followed may be 
regarded as a modification of those of Ray and Linneus, adapted to 
the present state of zoological science,’ the genus Eguus is placed 
between Cervina and Elephantine. After Elephas comes Tapirus, 
then Sus (Suina), next Rhinoceros (Rhinocerina), and Hyraz, fol- 
lowed by Hippopotamus, which leads to the family Dasypide com- 
mencing with the genus Manis, &c. I am not without hopes that — 
the remarks here offered on the natural affinities of the even-toed 
Ungulates may dispose the active Curator of our national zoological 
collections to reconsider his arrangement of the hoofed. species. 
In the Systema Vertebratorum by Charles L. Bonaparte, Prince 
of Canino (4to, 1840), the accomplished author, adopting my primary 
division of the class Mammalia into the. Placentalia and Implacen- 
talia or Ovo-vivipara, arranges the Ungulata, like Cuvier, into the 
Ruminantia and haud Ruminantia, but prefers the Linnean terms, 
Pecora and Bellue, for these orders respectively. The progression 
of the hoofed families is as follows :—ELEPHANTID, including Di- 
notherina and Elephantina: Sup, including Hippopotamina, Rhi- 
nocerotina, Tapirina, Suina, Anoplotherina: HyRracitp, including 
Hyracina: Equip, including Kquina ; which leads to the Camelide 
and the rest of the order PecoRA. | 
Prof. Milne-Edwards, in his excellent ‘Elémens de Zoologie,’ ad- 
heres to the system of Cuvier, as developed in the last edition of the 
‘Réegne Animal’ (1829), im which the ‘ Pachydermes’ and the 
‘ Ruminants’ are made equivalent groups and the genera are arranged 
as follows:—Fam. Proposcipiens. Hlephas, Mastodon. Fam. 
PACHYDERMES ORDINAIRES. A. le pied en quelque sorte four- 
chu: Hippopotamus, Sus, Phacocherus, Dicotyles, Anoplotherium. 
B. qui n’ont pas le pied fourchu: Rhinoceros, Hyrax, Paleotherium, . 
Lophiodon, Tapir. Fam. Lzes Soutpepes. Equus. Ord. RUMI- 
NANTIA, Camelus, &c. 
In thus imterposmg the Perissodactyles (odd-toed Pachyderms) 
between the pachydermal and ruminant groups of Artiodactyles 
(even-toed Ungulates), it would seem that Cuvier had abandoned 
his earlier views of the true affinities of the Horse as removing 
it from the Ruminants, and of the close relations of the even-toed 
Pachyderms, through the Anoplotherium, with the Ruminants. 
M. Lesson in his ‘ Manuel de Mammalogie,’ 12mo, 1827, makes 
the Pachydermes his 6th order, with the three divisions Probosci- 
diens, Pachydermes proprement dits, and Solipédes: the RUMINANS 
are the 7th order. 
The most elaborate revision of the groups and affinities of the 
Mammalia which has issued from the French school of Zoology since 
the decease of its great founder Cuvtmr, is that by M. Lerebouillet, en- 
titled ‘ Tableaux des Ordres, des Familles, et des Genres, des Mammi- 
féres, adoptés pour le Cours de Zoologie de la Faculté des Sciences, 
par M. Duvernoy: 4to, 1834. In this essay the three Cuvierian 
divisions PROBOSCIDIENS, PACHYDERMES ORDINAIRES and SoLi- 
