476 
SIR R. OWEN ON THE FOSSIL REMAINS OF TWO SPECIES 
Subsequent discoveries in Lord Howe’s Island may indicate sexual modifications in 
Meiolania, but the occipital and mandibular characters above defined, the subjects of 
Plates 1 and 2, are of higher taxonomic value. 
The main horn-core, b, in Meiolania, is shorter in proportion to its basal breadth ; 
the hinder protuberance is lower and has a longer base; the reticular sculpturing of 
the superficies of the larger horns and contiguous parts of the cranial wall is more 
strongly marked than in Megalania. Here, also, I may observe that, if the part 
marked x in Plate 30 be merely fracture, the nasal horn in the Moloch Saurian 
(‘Phil. Trans.,’ 1880, Plate 37, fig. 8) has not a bony support, and such might be the 
case in the horned Saurians of Lord Howe’s Island. 
The length of the imbedded portion of the skull of Meiolania platyceps, above des 
cribed, is 9-| inches ; the breadth across the bases of the biggest horn-cores is G-| inches. 
The subject of fig. 2, Plate 31, is the symphysial extremity of the mandible of a 
larger Meiolania, including similar modifications for support of a lower horny beak, 
and the commencement of the mandibular rami thence diverging. The anterior of the 
trenchant ridges, a, a, is notched in the middle ; the next is divided by a median 
channel. The partially preserved oral surface extends backward on a tract of bone, e, 
half an inch in vertical breadth or thickness, which overlies the smooth inner surface, f 
of the attached parts of the mandibular rami. The anterior trenchant border termi¬ 
nates at each outer end in a tuberosity, t, from which the corresponding border of the 
ramus descends, and. expands to form a smooth, broad, slightly concave surface, f, 
defining the upper part of so much of the ramus as is here preserved. The rough 
granulo-reticulate outer surface of the lower jaw, continued at right angles from the 
smooth upper surface, makes an abrupt bend inward to a broad, flattened, similarly 
sculptured, under-surface of the beginning of the ramus, where it extends freely 
backwards from the masticatory and symphysial part of the lower jaw. The breadth 
of the lower surface, at the fracture, is 1^ of an inch ; the depth of the thick ramus 
here, between the upper smooth and lower sculptured surfaces, is half an inch. The 
concave inner surface of the ramus, where it is continued from and undermines the 
hinder masticatory part of the symphysial end, is smooth. Tire breadth of the 
mandible at the fractured ends of the rami is 5 inches. This portion of jaw indicates 
a massive powerful bone. 
The above-described fossil reached me in a detached state. 
A second block of matrix includes an anterior vertebra, part of a scapula, and 
fragment of a humerus. 
Of the vertebra, the hinder part is exposed, the fore part of the centrum is 
imbedded in the matrix. A deep and well-defined concavity occupies the hind part of 
the centrum, showing an epicoelian character. This articular surface is continued upon 
a pair of processes extending backward, and slightly diverging from the hinder and 
under part of the centrum. Each process is short and thick, and terminates obtusely 
with an articular surface slightly convex, apparently for the attachment of a rib. The 
