165 
determination of the Hunterian specimen. For the apparently ex- 
tinct bird indicated by these fossils, the name of Lithornis vulturinus 
is provisionally proposed. 
3. Mr. Owen commences his description of the remains of an ex- 
tinct species of Serpent found at Sheppey, by pointing out the es- 
sential characters by which the vertebree of an Ophidian Reptile are 
distinguished. 
Vertebre joined enarthrodially by a deep anterior transversely 
oblong cup and a corresponding prominent posterior ball, and fur- 
ther articulated by projecting posterior oblique processes, wedged 
liked the carpenter’s tenon into a mortice, excavated in the anterior 
oblique processes of the succeeding vertebra, supporting moreover 
on each side of the fore part of the body an oblong convexity for 
the moveable articulation of the rib, can belong, Mr. Owen ob- 
serves, to no other than a reptile of the Ophidian order. 
One of the specimens described in this portion of the memoir, 
consists of about 30 vertebre possessing the above characters; also 
of a number of long slender ribs, having expanded concave vertebral 
extremities cemented irregularly together by a mass of indurated 
clay, and it forms part of the Hunterian collection of fossils; an- 
other specimen, consisting of 28 vertebree, and some others of less 
magnitude, belong to Mr. Bowerbank’s collection. All the speci- 
mens, Mr. Owen considers, are referrible to the same species, and 
they were all found at Sheppey. 
The vertebre in each specimen present the same conformation, 
and nearly the same size, being equal in this respect to those of a 
Boa Constrictor 10 feet long. They belong to the ordinary dorsal 
or costal series, and differ from those of the Boa and Python in their 
superior length as compared to their breadth and height. The ridge 
continued from the anterior to the posterior oblique processes on 
each side is less developed: the oblique processes themselves do not 
extend so far outwards; and the spinous process is narrower in its 
antero-posterior extent but longer. In the first two of these differ- 
ences, the fossil agrees with the Linnean Coluber and its subgenera, 
but differs from the Crotalus ; and in the remaining points it differs 
from Crotalus, Coluber, Naja and Trigonocephalus. The long 
and comparatively narrow spine, the outward prolongation of the 
upper angle of the posterior oblique processes, the uniform convexity 
of the costal protuberance, the uneven or finely wrinkled external 
surface of the superior arch of the vertebra, are characters which 
distinguish these Ophidian vertebrze from those of any other genus 
of the order with which Mr. Owen has been able to compare them. 
He therefore proposes to call the species provisionally Paleophis To- 
liapicus. 
The ribs are hollow as in all land serpents. 
From the agreement in the configuration of the under surface of 
the body of the vertebre of the fossil with that in the vertebree of 
the Boz and Pythons more nearly than with the Colubri, and in 
none of the differences above noticed indicating any obstacle to the 
