509 
are nearer to the upper than the lower surfaces of the centrums, and they in no way hide 
any part of the inferior surfaces of the latter. The neurapophysial surfaces were long 
fore and aft, and somewhat narrow, hut those of the pleurapophysial, on the other hand, 
were large and oblique, and somewhat narrow. 
In P. australis, Owen, there are two largo and two small venous foramina instead 
of only two large, as in the present case. Amongst other New Zealand species is P. 
crassicostatus, Owen,* the centrums of which, according to Sir .Tames Hector, “are deeply 
excavated beneath, with two venous foramina. The articular surfaces are elongately 
trausverse, forming a contracted oval, and only moderately concave with rounded 
niargins.”t In the Queensland bones the margins are distinctly flattened, and the 
ventral surface, instead of being excavated, is convex. The concavity mentioned by 
Hector is visible in his figures, and gives a character to the vertebrae not to be mistaken 
or overlooked. Furthermore, the centrums of the former have no definite tubercle, 
which is present in P. crassicostatus. 
Loc. Walker’s Table Mountain, Flinders Eiver (il/e^srs. Carson and Suther- 
land — National Mus., Melbourne) ; Pitchery Creek, Barrington’s Station, Central 
Queensland {S. J. W. Crammer — Mining and Geol. Mus., Sydney) ; Marathon 
(G. Sweet — Collir. Sweet, Melbourne). 
Some additional remains of Plesiosaurus have lately been described by the W riter,J 
consisting of vertebrse and ribs confusedly intermingled. No good purpose would be 
served by applying names to these bones, but the following is a general description of 
the fossils. 
In this mass we have the remains of at least four vertebrse, which, judging from the 
form and attached processes, are clearly those of the dorsal series. Only one, however, 
is in any degree perfect, the others having undergone fracture, and all abrasion. 
Intermingled with the vertebrse are portions of ribs, particularly two well-marked 
fragments, and an articular end of a third. 
The most perfect vertebra is five and a-quarter inches high, but the inferior 
margins of the centrum are not preserved, so that this measurement is somewhat under 
that of the perfect size of the bone. The edges of the articular surfaces are much 
Worn and decorticated, but, as preserved, the entire centrum is au inch and a-half in 
height, and the concave articular surface an inch and a-quarter. The length of the 
centrum, fore and aft, is an inch and three-quarters, and the breadth, or width, two 
inches. The neural spine, from the upper margin of the canal in the middle line, is 
three and three-quarter inches in height, but is shortened by fracture ; it is sharp, thin, 
and laterally compressed. At its base the spine is an inch and a-half thick from before 
backwards ; but at the broken upper extremity, the transverse width is a little less than 
an inch. It is very erect, and does not appear to have any posterior inclination, but 
the posterior zygopophysis would overhang the succeeding centrum to a slight extent 
when in apposition with it. The neural canal itself is broadly oval, measuring an inch 
in its longest diameter ; but the pre-zygopophysis is not preserved. The diapophysial 
support of the rib visible is placed very high up, and is directed backwards and upwards 
and forms the entire costal surface ; below this point the surface of the vertebra is 
much hollowed. The diapophysis is ledge-like, flattened to some extent above and below. 
* Geol. Mag., 1870, vii., p. 53. 
t Trans. N. Zealand In.st., 1874, vi., p. 342. 
t On additional Evidence of the occurrence of Plesiosaurus in the Mesozoic Rooks of Queensland. 
■Proc. Linn. Soc. N. S. Wales, 1888, iii., Pt. 2, p. 410, t. 8. 
