PRIMARY GROUPS OF MAMMALS. 529 
compressed) or, attypically, as nails (i. e. depressed). First digit (great 
rise toa hippos pus minor within the posterior cornu of t Caii 
by which the posterior lobe of the cerebrum is traversed. us of three 
namel; mola ooted. Incis four w: etypically, two 
all — in upper jaw suppressed. Placenta EAS disco 
Contains eight families, representing two sub-or APAE 
with five families, and LEMUROIDEA with three nanittie. S. 
(Feral Series.) 
II. ORDER FER. 
Legs with the proximal joints (humerus and femur) more or less 
inclosed in the common abdominal integumen. Digits with corneous 
appendages developed as claws: first digit of hind foot attypically re- 
ee kin 
molars settee adapted E carnivorous diet, o Pms ormore in e 
jaw being sectorial, followed by tubercular ones. yee rah ovpicalty 
six in each jaw, szaupann sity two or more suppressed. Placenta de- 
ciduate, zonary. Scaphoid and lunar consolidated into one bone. 
Contains twenty families, representing two sub-orders : CARNIVORA Or 
Fisstpep1a, with seventeen fa oe four of which are extinct, and 
PINNIPEDIA with three familie 
(Ungulate Series.) 
Legs with the nage joints more or less inclosed in the common 
abdominal integu Digits with corneous ,appendages developed as 
hoofs. r SSAB accu Teeth of three kinds (canines and incis- 
ors oO set exceptionally in part undeveloped), all encased in 
f ond 
mel: PEREA attypically with grinding surfaces. Scaphoid and lunar 
a. 
III. ORDER UNGULATA. 
Incisors ADOTE $. often, PERON in the upper jaw, re- 
duced in number or wholly suppressed : implanted by simple roots) with 
incisorial crowns. at with inferior (or, rather, posterior) surfaces with 
e cuboid as well as navicular: toes (not more than four —d 2 to d5— 
completely developed) with terminal joints encased in thick hoofs. Pla- 
centa non-deciduate (diffuse or cotyledonary). 
