4 
ANNALS OF THE QUEENSLAND MUSEUM. 
aware, has been made known respecting this reptile. It is therefore 
with great pleasure that I find myself in a position to make some 
little addition to our knowledge of its structure, provided always 
that co-identity between the type and its supposed co-types can be 
established. The type was said to be from the Flinders River, but 
the result of subsequent inquiry was the information that it had 
been sent to Sydney from Landsborough Creek, one of the primary 
affluents of the Thomson River, whose southerly directed water- 
course joins that of the Barcoo River, and with it loses itself further 
south. The watersheds of the two river?, inclining in opposite 
directions, are separated by so scanty a breadth of upland — if barely 
rising ground may be so called — that the distance of Landsborough 
Creek from O' Conn ell Creek is but little more than 80 miles, a 
space of old sea margin too small to compel us to believe that the 
remains of a Chelonian found on the one are not likely to belong to 
the same species as those discovered on the other. On the contrary,, 
it is, in the absence of hostile evidence, allowable to assume that any 
parts of a like reptile brought to light at O'Connell Creek are, by 
virtue of their proximity of location, specifically identical with 
JV". costata, Ow., and on this understanding treat the two specimens 
illustrating its cranial features in youth and maturity. 
The Immatttbe Skull : PI. iii, fig. 1. — This is an imperfect 
cranium which, chiefly on account of its comparatively small size, 
appears to be that of a young individual. It presents to view nothing 
more than the exterior of the right side of a skull, extending from 
the anterior end of the maxillary to within the anterior slope of the 
tympanic antrum. Fortunate in its entombment, it has not been sub- 
jected to a depressing force acting on its roof, consequently whatever 
features it has wherewith to instruct us,thesehave remained vertically 
in their normal form. The temporal region is protected by bone, 
presumedly by a post-frontal 14 mm. in breadth. The orbit is not 
at this period of life of greater size than in the adult, being in 
length 45 mm., in height 20 mm. ; its form would be represented by 
two parabolic lines, the lower one reversed and inversed The 
sclerotic plates are in place, forming a rosette of six plates of 
unequal size. The most interesting feature in this subject, however, 
is the armature of the jaw, consisting of four stout compressedly 
conical and backwardly curved processes half an inch in length 
from the edge of the maxillary, with indications of a fifth anteriorly. 
