While resembling the parabola in extending to infinity, the curve has closest affinities to the ellipse.
(X 20.) order, showing affinities on the one hand with the Corrodentia (book-lice and biting lice) and on the other with the Hemiptera (cicads, bugs, &c.) .
One of the two living species was, indeed, described so long ago as the year 1863, under the preoccupied name of Hyracodon, but attracted little or no attention, as its affinities were not fully recognized.
Here may be noticed three genera of large extinct marsupials from the Pleistocene of Australia whose affinities appear to ally them to the wombat-group on the one hand and to the phalangers on the other.
The affinities of the creature are clearly with the phalangers.