318 PEOPESSOE OWEN ON THE EOSSIL MAM5IAES OE ArSTEAUA. 
This portion (Plate XI. fig. 3; Plate XIII. figs. 4 and 6) fortunately inclnd^ the 
camassial and tubercnlav teeth, and by the “yfj^J^l^fxra^d Xn- 
with the answerable teeth (p m .) m the upper jaw of ThylacoUo (Plates XI. andXlN . 
fio- Tl I believe it to belong to the same species. 
®The Lwer camassial tooth consists only of the ‘blade,' wMch is t^ckest antenor y 
with an even trenchant edge, describing a slight concavity lengthmse, 
abraded by the play of the upper tooth upon the outer side of the edge The outside 
of the tooth (Plate XI fig. 3, p 4) is convex lengthwise, and also vertica y a e ore- 
Sm. Hit 4 4 .1 i. 
Ltically it is convex at the base and concave above, the base bem^ s g . =■ 
vertically The anterior margin of the tooth, which is the highest, us bounded by a 
Te cT ridge. The length o? the crown is 1 inch 8 lines; the height at its fore-part 
Tg hUhe thickness at the same part is 6 lines: the height -1 ‘hickn^s of the 
crown dimmish toward the back part. The smaU tubercular tooth 
Plate XIII. figs. 4 and 6, m i) is immediately behmd the piecedmg . i co s 
^stcfly than® the one above! of an anterior principal lobe and a small post^or one 
the anterior lobe is convex on both sides, subconical, with a worn 
antero-posterior extent of the crown is 7 lines; the same extent ^ J 
equals that of the upper sectorial, and the lower tubercular is so situated as to pla . 
3^movementso/thejaw,upontheuppertubercular. “themWrninpW 
there is the socket of a rudimental one, which cannot have exceeded o hue in its lon,c,^ 
diameter (ib. m ,). From this socket the coronoid process begins to nse 
and backward. It is broken off within half an inch of its ongin The ' 
fossa for the implantation of the tempoial muscle is preseived, 
strength of that muscle; the anterior boundaiy of the fossa is lei . ‘ 
forwLs. The ramus of the jaw preserves the same depth from tlm last s 
fore-part of that of the sectorial tooth. The symphysis (Plate XIII. fig 4, .s) be m, 
behind, at a vertical line dropped from a little in advance of the inidd e of the secto , . 
y , ; it is of a wide oval form. To judge from the cast, but little oi the J'"' 
to have been broken away fr'om the fore-part of the syniphysis. T \e upjm a ri , 
part shows the alveolus and base of a tooth (Plate XI. fig. o, c) whmh 1 as po ec ec 
obliquely upward and forward. It is separated by an interspace u o lines tom e 
sectorial, and would seem to be the sole tooth in advance of it. It * i esen- 
nroduced at the upper paid of the symphysis further thau is indicated by the pie, . 
cast it may have contained one or more incisors, and the broken tooth in question nia 
hole Llr canine. If, however, this be really the foremost tooth ot ‘ 
appear to be one of a pair of lai'ge incisors, according to the marsupial type i. 
by the Uaa-opodiice and PhaUnyistido!. However this may ultimate y P'Y’ " J,/ 
molar seriesfn each ramus of the lower jaw is redticed to tlm "Sliced 
the two small tuberculai-s; and it would seem, therefore, in the uppei J. , 
to the single sectorial and single tubercular on each side. It is possible t . . 
