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Show 1867.] DR. J. MURIE ON PHASCOLOMYS PLATYRHINUS. 801 an equal age (e. g. adult to adult or young to young) the same difficulty would not be encountered. In m y former paper (P. Z. S. 1865, p. 847) I have set down the specialities of P. platyrhinus, as compared with P. wombat, to be these four :-(a) The greater size of the cranium, (b) The greater relative breadth of the nasal bones, (c) The moderately deep tympanic excavation, (d) The more triangular form of the posterior palatine foramina. In elucidation of the proportional magnitude of the crania of the three species of Wombat I append the subjoined table. The first column represents the lately acquired skull of P. platyrhinus (the larger animal figured in Pl. X X X V . ) , and the two next columns those of the specimens of P. latifrons. They are each taken in inches and lines, and correspond to the table of admeasurements of skulls given in my former paper. The remaining columns respectively show in twelfths of an inch the average of seven specimens of P. platyrhinus, six of P. wombat, and four of P. latifrons. Measurements of Skulls and Series of Aver aye Proportions. Total length of cranium Greatest width, which is at the posterior part of the zygomatic arch Width of skull behind orbits, where con- | tracted by temporal fossa; J Width at anterior part of zygomatic arch ... Length from occipital crest to temporal fossa Length of nasal bones Width of same behind Width of same near apex Length of frontal bones Width of same between orbits Width of eaoh intermaxillary bone as seen | from above J Length of palate Width between anterior molars Width between posterior molars Width of both superior incisor teeth Depth of same taken singly Distance between incisor teeth (upper jaw) and molars Total extent of row of molar teeth Length of lower jaw Greatest breadth of same Jleight in a vertical line dropped from] coronoid process f Width of lower incisors Depth of the same § a.s> •* §. a. S»B* in. lin. 8 9 5 9 2 2 4 7 2 3 3 3 2 3 0 9 3 5 2 6 0 11 4 9 0 6 1 0 0 %\ 0 6 2 0 2 3 6 9 5 11 3 7 0 7\ 0 4£ Mr. Bartlett's specimen of P. latifrons, No. 1. in. lin. 6 8 4 9 1 7 3 10 1 11 2 3 2 4* 1 1 2 4\ 2 9 0 2 3 7\ 0 5 0 10£ 0 10 0 3 1 7\ 1 10 5 'S\ 4 bi 3 1* 0 G 0 3 Mr. Bartlett's specimen of P. latifrons, No. 2. in. lin. 6 3 4 3* 1 6 3 6* 1 11 2 1 2 2 1 0 2 2 2 5 0 2^ 3 5 0 4$ 0 9i 0 8* 0 3 1 6* 1 10 4 9 4 li 3 1 0 b\ 0 3 Average measurements of seven specimens of P. platyrhinus. lines. 92 67 24 53 26 34 26 10 34 29 8 52 4 10 9 5 17 26 71 68 36 7 4 Average measurements of six specimens of P. wombat. lines. 75 57 18 43 21 28 19 7 27 23 7 38 4 8 7 3 14 23 53 55 35 7 3 Average measurements of four specimens of P. latifrons. lines. 77 56 18 45 23 25 28 13 28 32 2 43 5 10 9 3 19 22 57 51 36 6 3 |