142 COPE. [Vou. Til. 
INTRODUCTORY REMARKS ON THE PHYLOGENY OF THE 
MAMMALIA. 
The following scheme expresses the classification of the Mam- 
malia as adopted by the writer. While it expresses the natural 
groupings and affinities, it is defective in that some of the 
definitions are not without exceptions : 
I. An interclavicle ; a large coracoid bone articulating with the sternum 
(Prototheria Gill). 
Marsupial bones ; fibula pene with ne end of 
astrapalus.. - =. . . « I. Monotremata. 
II. No “aside: Erricoid: a dal process codssified vote the scapula 
(Eutheria Gill). 
a. Marsupial bones (generally); palate with perforations; (vagina 
double; placenta and corpus callosum rudimental or wanting ; 
cerebral hemispheres small). (Didelphia de ae 
But one deciduous molar tooth . . . . . . 2. Marsupialia. 
aa. No marsupial bones; palate eeneally Erne (ene vagina; pla- 
centa and corpus callosum well developed). (Monodelphia de Bl.) 
B. Anterior limb reduced to more or less flexible paddles ; posterior 
limbs wanting (Mutilata). 
No elbow joint; carpals discoid, and with the digits separated by cartilage ; 
lower jaw without ascending ramus . . . . . . 3. Cetacea. 
An elbow joint; carpals and phalanges with normal articulations ; lower jaw 
with ascending ramus. . . Fad) Jip ViAZee 
BB. Anterior limbs with flexible joints ane) distinct digits ; ungual pha- 
langes not compressed and acute at apex! (Ungulata ”). 
y. Tarsal bones in linear series ;? carpals generally in linear series. 
Limbs ambulatory; teeth withenamel. . . . . . >. 5. Vaxeopoda. 
yy. Tarsal series alternating; carpal series linear, or reversed diplar- 
throus. : 
Cuboid bone partly supporting navicular, not in contact 
with astragalus . . . 5 : wa Va aie, Braobasceae 
yyy. Both tarsal and eee series more or less alternating; the inferior 
row inwards. 
Os magnum not supporting scaphoides ; cuboid supporting 
astragalus ; superior molars tritubercular . . . . 7. Amblypoda. 
Os magnum supporting scaphoides ; superior molars quad- 
rituberculané 4 Ue wees ei eel. oo es Ae eran 
1 Except the Hapalidee. 2 Lamarck, Zodlogie Philosophigue, 1809. 
3 Except in Dendrohyrax. * Except Pantolestes. 
5 This order includes the suborders Perissodactyla and Artiodactyla. It is the 
Ungulata of some authors. 
