5 
posterior pleural plates (Plate III., Fig. D) has longitudinal lines of 
like character. So far as we can learn from these examples of the 
species it seems to have been about equal in size with Chelodina 
oblonga. Loc. : Darling Downs. 
CHELYMTS ABATA, n.s.— This species, which is well distin- 
guished by the coarse ridge-and-furrow-like sculpture of its carapace, 
and the transverse direction of the ridges beneath the hinder part of 
the first vertebral shield, is almost as infrequent as the preceding. It 
is exemplified by three pleural and one pygal plate from the Darling 
Downs, and by two pleural plates from the Warburton River. The 
pleural plate, probably the fourth of the left side, figured on Plate IV., 
Fig. B, shows the characteristic sculpture almost in its pristine 
strength ; the rounded ridges equal to or greater than the deep 
furrows in breadth are seldom continuous, generally interrupted or 
by interosculation form loops and branches ; those on the upper or 
vertebral portion ascending obliquely, those beneath the costal shields 
descending. The younger bone, the fifth pleural plate apparently of 
the same side (Plate IV., Fig. C) has the same style of ornamental 
ribbing, but as in the subject of Fig. D, a still younger plate from the 
opposite side, the ribs on the part beneath the hinder portion of the 
vertebral shield are broken up into irregular tubercules not clearly 
marked in the drawing. The first pleural, one of the two Warburton 
River fossils, figured on the same Plate IY., Fig. A, shows that on the 
hinder portion of the first vertebral shield the ridges, formed probably 
by coalescence of the tubercules above mentioned, took a transverse 
direct direction, those on the costal part of the plate a strongly oblique 
direction upwards. To this species is referred the broadly pentagonal, 
radiately furrowed pygal plate represented by Fig. E, Plate IY. It 
is evidently from a Chehjmys, and more probably from this species 
than any other pygal in the collection. The second pleural from the 
Warburton River (Fig. F, Plate IY.) is a fragment of the fourth of 
the left side much abraded. In size G. arata appears not to have been 
larger than the recent G. macquaria. 
Gen. Chelodina. 
CHELODINA LNSCULPTA, n.s.— A species which is at present 
distinguished chiefly by the extreme degree to which the typical 
sculpture of the genus is developed by it. The inner surface of the 
first pleural (Plate V., Fig. A) shows that the curved pier sent up by 
the brachiosternal for the support of the carapace extended inwards 
towards the vertebrae as far as it does in G. oblonga, but was more 
forward in position, and further, that the convex surface for the 
reception of the pier was continuous with that of the process for the 
attachment of the vertebral centra, which is not the case in G. oblonga ; 
but the position of the pier, and consequently the longitudinal extent 
of the anterior opening of the test, appears to have been liable to con- 
siderable variation, for in the subject of Plate V., Fig. B, a second 
pleural of the same side, with attachment to the succeeding vertebrae, 
the pier was inserted on the posterior side of the second rib instead 
of that of the first. The specific character of the surface graving 
apparent in its peculiar strength and regularity is well seen in 
this example. On the vertebral portion of the plate each edge 
presents a row of long folds or bars while the middle is covered 
