466 



tig. 1, m 2), the coronal enamel is disposed on a simpler pattern, more in accordance with 

 that of the normal Kangaroos*. Moreover, as in the larger living and extinct species 

 of Macro/) us, the bony palate is entire (Plate XCVII. fig. 1). 



The usual permanent or adult series of five molars have remained in place and use in 

 our present fossil, whereas at the degree of wear shown by the last grinder, the first, if 

 not also the second, would have been shed in Macropits properf. 



In the maintenance of the adult series of five grinders the fossil resembles Osphranter, 

 Hal nidi itrus, and Stlienurus, but the premolar (ib. ib. p 3) differs in shape and proportion. 

 Its antero-posterior extent is but three fourths that of the next tooth (ib. d ■•) ; in 

 Osphranter and Petrogale (Plate XC. fig. 1) the premolar equals, in Halmaturits 

 and Sthenurus it exceeds, d * in that dimension. But in the fossil the transverse diameter 

 of the premolar in proportion to the length of the crown is greater than in any known 

 existing Kangaroo, and in this respect is equalled only by the extinct Procoptodons. As 

 in these, also, the front pier of the zygoma (ib. 21") has a more advanced position in rela- 

 tion to the molar series than in Macropits, Osphranter, or Ilalmaturus. But the chief 

 distinctive character of the present fossil is the great proportional length of the pre- 

 maxillaries (Plates XCVL, XCVIL, CV. 22, 22') and the concomitant backward position 

 of the incisive or premaxillary palatine foramina (ib. a), which are closer together, and 

 were separated by narrower processes of these bones, if so separated at all ; for the 

 foramina in the fossil seem to have been confluent, and were certainly short and parallel ; 

 whereas in Macropits, Osphranter, Halmaturits, and Petrogale (Plate XC. fig. 1, a a) 

 they are relatively longer, are wider apart, and usually with their narrow or pointed 

 hind ends convergent. 



The dental formula, i 3-3, c 0, m 5-5, and pattern of the grinding-surface of the molars 

 (Plate XCVII. fig. 2) being macropodal, the differential characters from known 

 recent and fossil Kangaroos are of subgeneric value, and call for the usual taxonomic 

 indication which heads the present section. 



§ 26. Palorchestes Azael, Ow. — The fore end of the premaxillaries is not quite entire, 

 but sufficient of the sockets of the three incisors of the right side remain to show that 

 not more than half an inch of the bone can there be wanting ; the teeth have dropped 

 out prior to fossilization. From the fore end of the skull to the premolar ( p 3) is 

 inches; the length of the molar series is 4 inches 6 lines. These two admeasurements 

 are relatively almost the same in Osphranter robustus, the length of its series of five 

 molars being 2 inches 2 lines, and that of the skull in advance of the premolar being 

 2 inches 3 lines ; the part of the skull behind the last molar in the fossil is 2 inches 

 9 lines in length. On this basis the entire skull of Palorchestes Azael may be 

 reckoned at about 16 inches in length. 



The extent of the diastema in the upper jaw supports an inference of a like extent in 

 the lower, and would show a nearer resemblance, in the latter respect, of Palorchestes to 

 Macropus, Osphranter, and other genera of normal Kangaroos, than to the extinct 



* riate LXXXI. fig. 10, m 2 (Macropus Titan). + Ib. ib. fig. 15 (Macropits Titan). 



