94 
FOSSIL JAWS OF MACROPODID.E, 
The lower premolar (PL xvi. fig. 1) before eruption simulates 
remarkably well the ledged upper tooth in several Macropods. 
The intero-posterior ledge-like cusp occupying half of the outer 
side is separated from the lobe posteriorly by a wide cleft, but 
within which a larger and a smaller oblique fold ascend on the 
inner side of the cusp; anteriorly the cusp joins the lobe by the 
incurving of its sharp edge, and anterior to this transverse sepi- 
ment are two cavities separated by a deep rib which ascending to 
the crest meets a corresponding one on the inner side of the 
crown, and with it forms a pronounced denticle on the crest. In 
the worn tooth (PL xvi. fig. 4) the structure is still recognisable. 
Examples — eleven. 
Mandibular. — An adolescent right ramus with all the cheek- 
teeth and with the incisor nearly entire (11126); accessory pro- 
cesses well marked — A right ramus with all the cheek-teeth but 
p. 4 perfect (11119); remains of the accessory processes distinct; 
aged — The associated rami of an aging mandible (8876), with the 
greater part of the ascending limbs; accessory processes as before 
— Portion of a right ramus with the last three molars (8873), 
adolescent — Alveolar portion of a right ramus with all the teeth 
mutilated but m. 1 , m. 2 (10409); processes nearly obsolete from 
wear; aged — Portion of a right ramus with the last three molars 
(10597); processes very distinct; adult — An adolescent right 
ramus with incisor and all the cheek-teeth but m. 4 , which has 
been broken off (11132); processes as before — A right ramus from 
a suckler with mp. 4 and m. 2 in its crypt; the exposed socket 
of the incisor showing that it was procumbent (10226); the 
processes on mp. 4 well marked — Fragment of a left ramus with 
m. 2 , m. 1 , and part of m. 4 (10596); processes as before; young — 
Both rami of an aged example all the teeth absent but the last 
three molars of the left side (11306). 
Sthenurus pales, n.s. 
Longitudinal links reduced to a tumescence on the floor of the 
mid valley and adjacent base of the fore lobe. Posterior basal 
